Question

Which expressions are equivalent to -7r2 + 12r - 8? Select TWO correct answers.

Answer
A (-5r²-r-4) + (-2r² - 13r+4)
B (-10r2+5r+ 2) + (3r² +8r-6)
C (10+7r-2) - (-6r² - 18+5r)
D (10+7r-r2) + (-6r² - 18+5r)
E (-5r²-r-4) - (2r² - 13r+4)

Answer 1

(A,D)

Explanation:

The two expressions that are equivalent to -7r^2 + 12r - 8 are:

A (-5r^2-r-4) + (-2r^2 - 13r+4)

D (10+7r-r^2) + (-6r^2 - 18+5r)

To verify that these expressions are equivalent to -7r^2 + 12r - 8, we can simplify them.

A (-5r^2-r-4) + (-2r^2 - 13r+4)

= (-5r^2 - 2r^2 - r - 13r - 4 + 4)

= (-7r^2 - 14r - 4)

D (10+7r-r^2) + (-6r^2 - 18+5r)

= (10 - 6r^2 + 7r - 18 + 5r)

= (-6r^2 + 12r - 8)

Both of these expressions simplify to -7r^2 + 12r - 8.