Question

помогите решить уравнение a) (x-2)(x+2)-x(x+5)=-8
b)25y-16=0

Answer 1

а)

$\displaystyle \tt (x-2)(x+2)-x(x+5)=-8\\\displaystyle \tt x^2-2^2-x\cdot x-x\cdot5=-8\\\displaystyle \tt x^2-4-x^2-5x=-8\\\displaystyle \tt -4-5x=-8\\\displaystyle \tt -5x=-8+4\\\displaystyle \tt -5x=-4\\\displaystyle \tt \bold{x=0,8}$

б)

$\displaystyle \tt 25y-16=0\\\displaystyle \tt 25y=16\\\displaystyle \tt y=\frac{16}{25}\\\displaystyle \tt \bold{y=0,64}$