Question

1) Resolva as equações a seguir:

a)18x - 43 = 65 (R: x = 6)

b) 23x - 16 = 14 - 17x (R: x = ¾)
c) 10y - 5 (1 + y) = 3 (2y - 2) – 20 (R: x = 21)
d) x(x + 4) + x(x + 2) = 2x2 + 12 (R: x = 2)
e) (x - 5)/10 + (1 - 2x)/5 = (3-x)/4 (R: x = -21)

Answer 1

a)18x - 43 = 65
18x=108
x=108/18
x=6

b) 23x - 16 = 14 - 17x
23x+17x=14+16
40x=30
x=30/40
x=3/4

c) 10y-5(1+y)=3(2y-2)-20
10y-5-5y=6y-6-20
5y-6y=-26+5
-y=-21
y=21

d) x(x+4)+x(x+2)=2x2+12
x^2+4x+x^2+2x=4x+12
2x^2+6x=4x+12
2x^2+2x-12=0
Delta
4-4.2.(-12)
4+96=100
Bhaskara
-2(+ou-)10/4
(-)--> x=-3
(+)--> x=2

e) (x - 5)/10 + (1 - 2x)/5 = (3-x)/4
MMC
2x-10+4-8x=15-5x
-6x-6=15-5x
-x=21
x=-21