Question

Which of the following represents the area of a rectangle whose length is 5x - 3 and whose width is
x + 7?
5x2 - 21
5x2 + 9x - 21
5x2 + 32x - 21
5x2 - 32x - 21

Answer 1

Expand$$ (5x-3)(x+7) = 5x^2 + 32x - 21$$

Answer 2

Area = length * width
\[(5x-3)(x+7)\]FOIL it
\[5x ^{2}+35x-3x-21\]
\[5x ^{2}-32x-21\]

Answer 3

no this is right (5x−3)(x+7)=5x2+32x−21

Answer 4

@deezil_wood: Check for the sign's ;)

Answer 5

oh yeah duh don't know where that -32 came from lol

Answer 6

$$35x-3x = +32x \neq -32x $$

Answer 7

it's happens, obvious typo :)

Answer 8

Yes thx for the explanation :p

Answer 9

you are welcome :P :D