Question

Помогите пожалуйста ​

Answer 1

Формулы:

$\displaystyle \tt (a+b)^2=a^2+2ab+b^2\\(a-b)^2=a^2-2ab+b^2$

Решение примеров:

$\displaystyle \tt 1) \: (3m+5n)^2=(3m)^2+2\cdot3m\cdot5n+(5n)^2=9m^2+30mn+25n^2\\2) \: (x-4y)^2=x^2-2\cdot x\cdot4y+(4y)^2=x^2-8xy+16y^2\\3) \: (10x+2y)^2=(10x)^2+2\cdot10x\cdot2y+(2y)^2=100x^2+40xy+4y^2$

Answer 2

$1)(3m+5n)^2=(3m)^2+2*3m*5n+(5n)^2=3^2m^2+2*3*5mn+5^2n^2=9m^2+30mn+25n^2\\ \\ \\ 2)(x-4y)^2=x^2-2*x*4y+(4y)^2=x^{2}-2*4xy+4^2y^2=x^{2}-8xy+16y^2\\ \\ \\ (10x+2y)^2=(10x)^2+2*10x*2y+(2y)^2=10^2x^2+2*10*2xy+2^2y^2=100x^2+40xy+4y^2$