Question

Помогите срочно дам 20 баллов!
a) (7a-b+2)(a-b-3)
b) (2a-2b-2)(a-b-2)
c) (3a-5-2b)(3a-2b)

a) 3x(y+2x)
b) (2x-y)*0.5xy
c) 3xy^{2}(\frac{1}{3} x-y)
f) (0.3x^{2}-9xy)÷(3x)
g) (x^2y^5-x^7y^3)÷(x^2y^3)

Answer 1

a) (7a-b+2)(a-b-3) = 7a²-7ab-21a-ab+b²+3b+2a-2b-6 = 7a²-8ab-19a+b²+b-6

b) (2a-2b-2)(a-b-2) = 2a²-2ab-4a-2ab+2b²+4b-2a+2b+4 = 2a²-4ab-6a+2b²+6b+4

c) (3a-5-2b)(3a-2b) = 9a²-6ab-15a+10b-6ab+4b² = 9a²-12ab-15a+10b+4b²

a) 3x(y+2x) = 3xy+6x²

b) (2x-y)*0.5xy=x²y-0.5xy²

c) 3xy^{2}(\frac{1}{3} x-y) = x²y²-3xy³

f) (0.3x^{2}-9xy)÷(3x) = (0.3x-9xy)/3 = (3x(0.1-3y))/3 = x(0.1-3y)

g) (x²y⁵-x⁷y³)÷(x²y³) = x²y³(y²-x⁵) ÷ x²y³ = y²-x⁵