Question

Which expressions are equivalent to 5 x-15? Select three options.

5 (x + 15)

5 (x-3)

4 x + 3 y-15- 3 y + x

-7 y-6 x- 8 y + x

-20 - 3 x + 5 + 8 x


PLSSS help my teacher already thinks i'm going crazy!

Answer 1

`b) 5 (x-3)\\c) 4 x + 3 y-15- 3 y + x\\e) -20 - 3 x + 5 + 8 x`

Explanation:

We are given the following expression in the question:

`5x-15`

a)

`5 (x + 15)\\=5(x) + 5(15)\\=5x + 75`

which is not equivalent to the given expression.

b)

`5 (x-3)\\=5(x)-3(5)\\=5x-15`

which is equivalent to the given expression

c)

`4 x + 3 y-15- 3 y + x\\=4x+x+3y-3y-15\\=5x-15\\=5(x-3)`

which is equivalent to the given expression.

d)

`-7 y-6 x- 8 y + x\\=-7y-8y-6x+x\\=-15y-5x\\=-5(x+3y)`

which is not equivalent to the given expression.

e)

`-20 - 3 x + 5 + 8 x\\=-3x+8x-20+5\\=5x-15`

which is equivalent to the given expression.