Question

Considere a igualdade y=3x/2 - x(1-x)/4 se y=-1 quais serão os valores reais correspondentes de X?

Answer 1

-1=3x/2-x(1-x)/4
-1=(3x/2).2 -1x+x²/4
-1=6x/4-1x+x²/4
-1=6x-1x+x²/4
-1.4=5x+x²
-4=x²+5x
x²+5x+4=0

Δ=b²-4.a.c
Δ=5²-4.1.4
Δ=25-16
Δ=9

x= -b+-√Δ/2.a
x´=-5+√9/2.1
x´=-5+3/2
x´=2/2
x´=1

x´´=-5-3/2
x´´=-8/2
x´´= -4