Question

2(-3x+5)^2
(x-2)(x+2)-2x(5-x) помогите!!!

Answer 1

Объяснение:

$2( - 3x + 5) {}^{2} = 2(9x {}^{2} - 30x + 25) = 18x {}^{2} - 60x + 50$

$(x - 2)(x + 2) - 2x(5 - x) = x {}^{2} - 2 {}^{2} - 2x(5 - x) = x {}^{2} - 4 - 2x(5 - x) = x {}^{2} - 4 - 10x + 2x {}^{2} = 3x {}^{2} - 4 - 10x$

Answer 2

$(a-b)^2=a^2-2ab+b^2\\\\(a-b)(a+b)=a^2-b^2\\\\\\2(-3x+5)^2=2(5-3x)^2=2(5^2-2\cdot5\cdot3x+(3x)^2)=\\\\=2(25-30x+9x^2)=50-60x+18x^2\\\\\\(x-2)(x+2)-2x(5-x)=x^2-2^2-10-2x^2=\\\\=x^2-4-10-2x^2=3x^2-4-10x$