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Solve the linear equation for , paying strict attention to directional negative signs and distributive operations: .
Answer and steps
Final answer
Steps
Expand both sides using the distributive property
To solve the linear equation, systematically expand both sides using the distributive property, combine like terms, and then isolate the variable .
Be especially careful with negative signs when distributing across parentheses:
- A negative sign in front of parentheses reverses the sign of every term inside: .
- Multiplying by a negative factor reverses the signs: .
Left-hand side:
- Distribute the negative sign to :
- Distribute to :
- Combine these parts:
Right-hand side:
- Distribute to :
- Distribute the negative sign to :
- Combine these parts:
Equate the simplified expressions
Isolate the variable term on one side
Subtract from both sides to collect the variable terms on the left:
Add to both sides to isolate the variable term:
Solve for
Divide both sides by :
Common Pitfall to Avoid
When a minus sign precedes parentheses, such as or , remember that the subtraction distributes to both terms inside. Writing instead of is a frequent sign error that alters the entire result.
Typical errors
01 The student forgets to distribute the leading negative sign to the second term inside the first set of parentheses, treating -(4 - 3w) as -4 - 3w, resulting in w = -1/3.
Sample Student Work
Reviewed by ACEpath TeacherStep-by-Step Review
Walk Through It with Your Teacher- Step 1
-(4 - 3w) - 5(2 - w) = -2(w + 7) - (6 - 4w) -4 - 3w - 10 + 5w = -2w - 14 - 6 + 4w
Correct-4 + 3w - 10 + 5w = -2w - 14 - 6 + 4w
When expanding , the negative sign must distribute to both terms inside the parentheses: . You left the second term as .
- Step 2
2w - 14 = 2w - 20 2w - 14 = -20 + 2w
Correct8w - 14 = 2w - 20
You correctly combined the terms from your previous line (), but because of the sign error in the first step, both sides ended up with , leaving an apparent contradiction rather than a solvable linear equation.
WHAT YOU DID WELL
Compliments from Your TeacherYou correctly distributed into , taking care of the double negative.
You accurately distributed into on the right-hand side.
You correctly distributed the minus sign across into .
You combined your simplified algebraic terms consistently on both sides.
THE ERROR
Where Your ACEpath Teacher Spotted the MistakeYou distributed the leading negative sign to but forgot to flip the sign of to .
WHY IT HAPPENED
ACEpath Teacher's DiagnosisTreating a leading minus sign before parentheses as merely attaching to the first term rather than multiplying every term inside by .
REASONING PATH
Your ACEpath teacher’s suggested approach- Negation as Multiplication by -1
Whenever you see a minus sign directly before parentheses, write an explicit in front to remind yourself to multiply each term inside by .
CORRECTED PATH
ACEpath Teacher's DemonstrationDistribute correctly across all parentheses:
Combine like terms on both sides:
Subtract from both sides:
Add to both sides:
Divide by :
w = -1
02 The student fails to distribute the negative sign when expanding -5(2 - w), writing -10 - 5w instead of -10 + 5w, leading to -2w - 14 = 2w - 20 and w = 3/2.
Sample Student Work
Reviewed by ACEpath TeacherStep-by-Step Review
Walk Through It with Your Teacher- Step 1
-4 + 3w - 10 - 5w = -2w - 14 - 6 + 4w
Correct-4 + 3w - 10 + 5w = -2w - 14 - 6 + 4w
When distributing into , multiplying the negative constant by the subtracted variable gives . You wrote instead of .
- Step 2
-2w - 14 = 2w - 20
Correct8w - 14 = 2w - 20
You correctly combined like terms based on your previous line, but the result was affected by the earlier sign error.
- Step 3
-4w - 14 = -20 -4w = -6
Correct6w - 14 = -20 6w = -6
Your algebraic manipulations of subtracting and adding were mathematically valid, but carried forward the incorrect variable coefficient.
- Step 4
w =
Correctw = -1
You divided correctly by to isolate , but the propagated error led to instead of .
WHAT YOU DID WELL
Compliments from Your TeacherYou correctly distributed the negative sign across to obtain .
You correctly expanded the right-hand side expressions and .
You maintained sound equation-balancing steps throughout the rest of your solution.
THE ERROR
Where Your ACEpath Teacher Spotted the MistakeYou treated as instead of , losing track of the fact that multiplying two negative signs yields a positive term.
WHY IT HAPPENED
ACEpath Teacher's DiagnosisWhen expanding parentheses preceded by a negative factor and containing an internal subtraction, the interaction between the outer negative and the inner minus sign was overlooked.
REASONING PATH
Your ACEpath teacher’s suggested approach- Double Negative in Distribution
Always treat subtraction inside parentheses as addition of a negative number: .
CORRECTED PATH
ACEpath Teacher's DemonstrationCorrectly expand both sides:
Combine like terms on each side:
Subtract from both sides:
Add to both sides:
Divide by :
w = -1
03 The student fails to distribute the negative sign to the second term in -(6 - 4w) on the right side, writing -6 - 4w instead of -6 + 4w, which yields 8w - 14 = -6w - 20 and w = -3/7.
Sample Student Work
Reviewed by ACEpath TeacherStep-by-Step Review
Walk Through It with Your Teacher- Step 1
-4 + 3w - 10 + 5w = -2w - 14 - 6 - 4w
Correct-4 + 3w - 10 + 5w = -2w - 14 - 6 + 4w
When distributing the negative sign across , remember that . Distributing across yields , not .
- Step 2
8w - 14 = -6w - 20
Correct8w - 14 = 2w - 20
You correctly combined like terms based on your previous line, but the right-hand side was affected by the earlier sign error.
- Step 3
14w - 14 = -20 14w = -6
Correct6w - 14 = -20 6w = -6
Your steps to isolate the variable term were performed correctly based on your intermediate equation.
- Step 4
w = -
Correctw = -1
You simplified the fraction correctly from your previous step, but the final value is incorrect due to the sign error in step 1.
WHAT YOU DID WELL
Compliments from Your TeacherYou correctly distributed the negative sign and coefficients across , , and .
You combined like terms systematically on both sides of the equation.
You executed the properties of equality accurately to isolate the variable.
THE ERROR
Where Your ACEpath Teacher Spotted the MistakeYou treated as instead of flipping the sign of to .
WHY IT HAPPENED
ACEpath Teacher's DiagnosisIncomplete distribution of the leading negative sign across parentheses containing a subtracted term, treating the minus sign in front of the parentheses as only attaching to the leading term.
REASONING PATH
Your ACEpath teacher’s suggested approach- Distribute to every term
Draw arrows from the outside minus sign or write an explicit in front of the parentheses to make sure both terms change their signs.
CORRECTED PATH
ACEpath Teacher's DemonstrationExpand the right-hand side with the correct sign: .
Combine like terms on both sides: .
Subtract from both sides: .
Add to both sides: .
Divide by : .
w = -1
Lock it in
What does a negative sign immediately in front of parentheses do to the signs inside, such as in ?
It reverses the sign of every term inside: because you are multiplying by .
Similar question
Solve for : .
Answer
. Distribute the negative: .
Solve for : .
Answer
. Expand both sides: .
Solve for : .
Answer
No solution. Expand: . Subtracting gives , which means the equation is an identity with infinitely many solutions (all real numbers satisfy it).