Question

Решить всееенее!!!!!!!! 1Враиант

Answer 1

Объяснение:

1)

$a)\ (3y-4)^2=9y^2-24y+16.\\b)\ 25t^2+30t+9=(5t)^2+2*5t*3+3^2=(5t+3)^2.$

2)

$a)\ 17^2-34*7+7^2=17^2-2*17*7+7^2=(17-7)^2=10^2=100.\\b)\ \frac{67^2-33^2}{15^2-25} =\frac{(67-33)*(67+33)}{15^2-5^2} =\frac{34*100}{(15-5)*(15+5)} =\frac{3400}{10*20} =\frac{3400}{200}=17.$

3)

$(2x-5y)^3=(2x)^3-3*(2x)^2*5y+3*2x*(5y)^2-(5y)^3=\\=8x^3-60x^2y+150xy^2-125y^3.$