Question

Решите уравнение:
(x + 7,2)(x − 8,1) = 0

Answer 1

(х+36/5)×(х-81/10)=0
х+36/5=0
х-81/10=0
х=-36/5
х=81/10
х=-36/5; Х=81/10

Answer 2

x^2-8.1x+7.2x-58.32=0
x^2-0.9x-58.32=0
D=0.81+233.28=234.09
x1=0.9-15.3/2=-7.2
x2=0.9+15.3/2=8.1