Question

CALCULE O VALOR DE X NAS PROPORÇÕES:

A) 4/2X = 6/X +2 B) 5X/X+1 = 2/5

Answer 1

a) 4x/2=6/x + 2 (*2x)
4x²=12+4x
4x²-4x-12=0 (/4)
x²-x-3=0 usar bhaskara
x= 1+-√Δ/2
Δ=(-1)²-4*1*(-3)=1+12=13
x'=1+√13/2
x'=(1+3,60)/2=2,30
x"=(1-3,6)/2= -1,30

b) 5x/(x+1)=2/5 *(x+1)
5x=2(x+1)/5
25x=2x+2
25x-2x=2
23x=2
x=2/23 ou 0,09