Andy and Sylvie each incorrectly simplified the expression -3 - 4(2x - 3). Andy wrote -14x + 21 and Sylvie wrote -8 - 6. Explain their errors and give the correct answer.

Question

My answer: What Andy did wrong is adding instead of subtracting and adding the negative in the wrong place. What Sylvie did wrong is that there is no variable included in her expression and she subtracted wrong. The correct answer is supposed to be -14x - (-21) or -15 - 8x.

Am I wrong?

Answer 1

The figures show the dimensions of a tennis court and a basketball court given in terms of the width x in feet of the tennis court.

Tennis: W:x L: 2x + 6
Basketball: W:1/2x + 32 L: 3x - 14

A: Write an expression for the perimeter of each court.
B: Write an expression that describes how much greater the perimeter of the basketball court is than the perimeter of the tennis court.
C: Suppose the tennis court is 36 feet wide. Find all dimensions of the two courts.

My answers:
A: (6x + 12) + (6 1/2x - 46)
B: (6 1/2x - 46) - (6x + 12)
C: (4x + 84) + (6 1/2x - 46)

Am I wrong?

Answer 2

On the first one,
-3 - 4(2x - 3)
-3 - 8x + 12
-8x+9

Andy did (-4-3)(2x-3)

For the next one,
(A) perimeters
Tennis: 2(W+L) = 2(x + 2x+6) = 6x+12
Basketball: 2(W+L) = 2(x/2+32 + 3x-14) = 7x+36

(B) (7x+36)-(6x+12) = x+24

(C) x/2 + 32 = 36
x/2 = 4
x = 8

Tennis: 8x22
Basketball: 36x10

Answer 3

thinks for the answer