SAT Mathematics Practice Test 3

Question : 26 of 58

Marks: +1, -0

$3x^2-5x+2$
$5x^2-2x-6$
Which of the following is the sum of the two polynomials shown above?

$8x^2-7x-4$
$8x^2+7x-4$
$8x^4-7x^2-4$
$8x^4+7x^2-4$

Solution:

The sum of the two polynomials is

(3x^2−5x+2) +(5x^2−2x−6).

This can be rewritten by combining like terms:

(3x^2−5x+2)+(5x^2−2x−6)=(3x^2+5x^2)+(−5x−2x)+(2−6)=8x^2-7x−4.

Choice B is incorrect and may be the result of a sign error when combining the coefficients of the x-term.
Choice C is incorrect and may be the result of adding the exponents, as well as the coefficients, of like terms.
Choice D is incorrect and may be the result of a combination of the errors described in B and C

Go to Question:

Prev Question

Next Question