Question

Решите уравнения √x^3-4=11 и √5x+1=1-x

Answer 1

√x³-4=11
x³-4≥0 U x³-4=121
x³≥4 U x³=125
x=5

5x+1≥0 U 1-x≥0
x≥-0,2 U x≤1
x∈[-0,2;1]
5x+1=1-2x+x²
x²-7x=0
x(x-7)=0
x=0 U x=7∉[-0,2;1]