which polynomial correctly combines the like terms and expresses the given polynomial in standard form? 9xy³ -4y⁴ -10x²y² + x³y + 3x⁴ + 2x²y² - 9y⁴

3x^4+(x^3)y-8x^2y^2+9xy^3-13y^4

Step-by-step explanation:

3x^4+(nothing)=3x^4

x^3y+(nothing)=x^3y

-10x^2y^2=2x^2y^2=-8x^2y^2

9xy^3+(nothing)=0

-4y^4-9y^4=-13y^4

Add it all up and write the terms by descending order of exponent value, and u get my answer.

the answer is b. 60. each interior angle in 120, so the exterior angle must be 60 in order to add up to 180

step-by-step explanation:

step-by-step explanation: