Answer:
19x^7y^16
Step-by-step explanation:
And usually means to add, so combine your like terms:
12x^5y^7 + 7x^2y^9
12 + 7 = 19
x^5 + x^2 = x^7
y^7 + y^9 = y^16
(12x⁵ y⁷) * (7x²y⁹) = (12*7) * (x⁽⁵⁺²⁾ ) (y⁽⁷⁺⁹⁾)
= 84x⁷y¹⁶
In exponents multiplication, if base are same, then add the powers.
xᵃ * xᵇ = x⁽ᵃ⁺ᵇ⁾
