Question

Уравнение.
3(x+5)-x^2=(2-x)(2+x)

Answer 1

3(x+5)-x^2=(2-x)(2+x)
3x+15-x^2=4-x^2 (убираем x^2)
3x+15=4
3x=4-15
3x=-11
x=-11/3
x=-3 2/3