Question

Найдите корни уравнения:1) x×x+60=85;(x×x-23)×9=17;(x×x×x+38)÷13=5;(149-x×x×x)×7=168.

Answer 1

1) x² + 60 = 85; x² = 85 - 60; x² = 25; x = √25; x = 5
2) (x² - 23) × 9 = 17; x² - 23 = 17/9; x² = 17/9+23; x = √(17/9+23); x = 4.98 ??
3) (x³+38)/13 = 5; x³+38 = 5×13; x³ = 65 - 38; x³ = 27; x = ∛27; x = 3
4) (149 - x³)×7=168; 149-x³=168/7; -x³=24-149; -1×(-x³= -125); x³=125;             x = ∛125; x = 5