find the sum of $2x^{2}+5x + 7$ and $-10x^{2}-7x + 1$.

Explanation:

Step1: Combine like - terms of $x^2$

$(2x^2)+(- 10x^2)=(2 - 10)x^2=-8x^2$

Step2: Combine like - terms of $x$

$(5x)+(-7x)=(5 - 7)x=-2x$

Step3: Combine constant terms

$7 + 1=8$

Step4: Write the sum

The sum is $-8x^2-2x + 8$

Answer:

$-8x^2-2x + 8$