Question

1.(2x-1)^2-4(x-2)(x+2)=0
2.(3a-b)^2-(3a+b)^2
3.(a+(b-c))
1.Решите уравнение.
2,3.Раскройте скобки.

Answer 1

$1. (2x-1)^2-4(x-2)(x+2)=0 \\ 4x^2-4x+1-4(x^2-4)=0 \\ 4x^2-4x+1-4x^2+16=0 \\ -4x+17=0 \\ 4x=17 \\ x= \frac{17}{4}=4,25$
$2. (3a-b)^2-(3a+b)^2=9a^2-6ab+b^2-(9a^2+6ab+b^2)=$$9a^2-6ab+b^2-9a^2-6ab-b^2=-12ab$
$3. a+(b-c)=a+b-c$