Question

Calcule o valor de x nas equações, sendo U=Q

exemplos: a) 4(x + 3) = 20
b) 5(2x - 1) = 2(x + 4)
c) 10 - 2(x + 3) = 8 + 3(2x + 5)
d) x - 2( x - 1 ) = 4 - 3(x - 2)

Answer 1

A) 4(x+3) =20
4x+3×4=20
4x + 12 =20
4x = 20-12
4x = 8
X= 8/4
X =2
B)5(2x-1) =2(x+4)
5×2x - 1×5 = 2x + 2×4
10x -5 = 2x +8
10x - 2x = 8 +5
8x = 12
X = 12/8
X=3/2 = 1,5
C) 10 - 2(x+3) = 8 +3(2x+5)
10 -2x -6 = 8 + 6x + 15
2x + 4 = 6x + 23
2x -6x = 23- 4
-4x = 19 (-1)
4x= -19
X = -19/4= - 4,75
D) x-2(x-1) = 4 -3 (x-2)
X -2x +2 = 4 -3x +6
-X +2 = -3x +10
-x +3x = 10 -2
2x = 8
X= 8/2 = 4

Olhar se o valor de X, sendo U=Q . Se não pertencer é vazio.

Answer 2

 a) 4(x + 3) = 20
4(x+3)÷4=20÷4
x+3=5
x+3-3=5-3
x=5-3
x=2

b) 5(2x - 1) = 2(x + 4)
5×2x-5=2x+2x4
10x-5=2x+8
10x-2x-5=2x-2x+8
10x-2x-5+5=8+5
10x-2x-5=8+5
(10-2)x=8+5
8x=13
8x÷8=13÷8
x=13÷8
x=13/8

c) 10 - 2(x + 3) = 8 + 3(2x + 5)
10-2x2x3=8+3x2x+3x5
10-2x-6=8+6x+15
4-2x=23+6x
4-2x-6x+4=6x-6x+23
4-2x-6x4-4=23-4
(-2-6)x19
-8x=19
x=-19/8

d) x - 2( x - 1 ) = 4 - 3(x - 2)
x-2x-2x(-1)=4-3x-3x(-2)
-x+2x+2=4-3x+6
1x-2x=4-3x+6
(1-2)x
-1x
-x2=10-3x
-x+3x+2=-3x+3x+10
-x+3x+2-2=10-2
-x+3x+2=10
-1x+3+2=10
(-1+3)x
2x=8
2x÷2=8÷2
x=8÷2
x=4