Which values make this equation true? (5x^7 y^5)=-20x^a y^ba.) a=11, b=7b.) a=11, b=10c.) a=28, b=7d.) a=28, b=10

When multiplying terms with exponents, just add the exponents together.

You have x^7 and x^4, so 7 +4 = 11

Y^2 and Y^5 = 2+5 = 7

so it would be -20x^11 y^7

The answer is A.) a=11, b=7