Question

1) resolva as equações a seguir

a) 3x (x + 2) = 0
b) x (2x + 5) = 2x
c) 9x*2 = 54x
d) (x - 5)(x - 6) = 30

Answer 1

a)3x²+6x=0
Δ=b²-4·a·c
Δ=6²-4·3·0
Δ=36-12·3·0
Δ=36-26·0
Δ=36



x'=-b+√Δ/2·a
x'=-6+6/6
x'=0/6


x''=-6-6/6
x''=-12/6







b)2x²+5x-2x=0
2x²+3x=0

Δ=3²-4·2·0
Δ=9-8·0
Δ=9



x'=-3+3/4
x'=0/4

x''=-3-3/4
x''=-6/4









c)9x²-54x=0


Δ=-54²-4·9·0
Δ=2.916-36
Δ=2.916


x'=54+54/18
x'=108/18
x'=6

x''=54-54/18
x''=0/18





d)x²-6x-5x+30-30=0
x²-11x+0=0


Δ=-11²-4·1·0
Δ=121-4·0
Δ=121



x'= 11+11/2
x'=22/2
x'=11

x''=11-11/2
x''=0/2