Question

Aflati x apartine lui N daca: a) x+3/x-1 = 9/7 ; b) 4/x la putere 2-2 = 2/7; c) 2/x la puterea 3 = 1/4 ; d) 2x la puterea 2/3x la puterea 2 + 4 = 1/2

Answer 1

a) (x+3)/(x-1) = 9/7
9(x-1)=7(x+3)
9x-9=7x+3
2x=12
x=6

b) 4/(x²-2) = 2/7
2(x²-2)=28
x²-2=14
x²=16
x=4

c) 2/x³ = 1/4
x³=8
x³=2³
x=2

d) 2x²/(3x² + 4) = 1/2
3x²+4=4x²
x²=4
x=2