Question

1) Resolva as equacoes do 1 grau
a) 4 (x+5)+3(x + 5)= 21
b) 8 (x - 1) = 8 - 4 ( 2 x - 3)
c) 2 (x + 5) - 3 (5 - x) = 10
d) 4 x - 1 = 3 ( x - 1)
e) 3 (x- 2) = 2 x -4

Answer 1

a) 4 (x + 5) + 3 (x + 5) = 21
4x + 20 + 3x + 15 = 21
4x + 3x = 21 - 20 - 15
7x = - 14
x = - 14 ÷ 7
x = - 2

b) 8 (x - 1) = 8 - 4 (2x - 3)
8x - 8 = 8 - 8x + 12
8x + 8x = 8 + 12 + 8
16x = 28
x = 28 ÷ 16
x = 1,75

c) 2 (x + 5) - 3 (5 - x) = 10
2x + 10 - 15 + 3x = 10
2x + 3x = 10 - 10 + 15
5x = 15
x = 15 ÷ 5
x = 3

d) 4x - 1 = 3 (x - 1)
4x - 1 = 3x - 3
4x - 3x = - 3 + 1
x = - 2

e) 3 (x - 2) = 2x - 4
3x - 6 = 2x - 4
3x - 2x = - 4 + 6
x = 2

Answer 2

$4 (x+5) + 3(x+5) = 21$
$4x+20+3x+15=21$
$4x+3x=21-20-15 7x=-14 x= -14/7 x=-2$

$b) 8(x-1)=8-4(2x-3) 8x-8=8-8x+12 8x+8x=8+12-8 16x=12 x=12/16 x=3/4.  c) 2(x+5)-3x(5-x)=10$$2x+10-15+3x=10 5x=10-10+15 5x=15 x=15/5 x=3$

d)
$4x-1 = 3(x-1) 4x-1=3x-3 4x-3x=3+1 x=4$


e)
$3(x-2) = 2x-4 3x-6=2x-4 3x-2x=-4+6 x=2$