Question

Помогите пожалуйста 4 и 5.

Answer 1

$0.64-y^2=0 \ y^2=0.64 \ y_1= sqrt{0.64},y_2=-sqrt{0.64} \ y_1=0.8,y_2=-0.8 \ \ z^2-7=0 \ z^2=7 \ z_1= sqrt{7},z_2=- sqrt{7}$