SAT Math : How to add trinomials

Study concepts, example questions & explanations for SAT Math

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Example Questions

Example Question #41 : Variables

Subtract \(\displaystyle 2x^2-3x+6\) from \(\displaystyle 4x^2+10x-11\).

Possible Answers:

\(\displaystyle -2x^2-13x-17\)

\(\displaystyle -2x^2-13x+17\)

\(\displaystyle 2x^2-13x+17\)

\(\displaystyle 2x^2+13x-17\)

Correct answer:

\(\displaystyle 2x^2+13x-17\)

Explanation:

Step 1: We need to read the question carefully. It says subtract from. When you see the word "from", you read the question right to left. 

I am subtracting the left equation from the right equation.

Step 2: We need to write the equation on the right minus the equation of the left.

\(\displaystyle 4x^2+10x-11-(2x^2-3x+6)\)

Step 3: Distribute the minus sign in front of the parentheses:

\(\displaystyle 4x^2+10x-11-2x^2+3x-6\)

Step 4: Combine like terms:

\(\displaystyle 4x^2-2x^2=2x^2\)
\(\displaystyle 10x+3x=13x\)
\(\displaystyle -11-6=-17\)

Step 5: Put all the terms together, starting with highest degree. The degree of the terms is the exponent. Here, the highest degree is 2 and lowest is zero.

The final equation is \(\displaystyle 2x^2+13x-17\) 

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