Question

resolva as seguintes equações de 1º grau
a) x-5 = 8
b) x-9 = 16
c) x-7 = 42
d) 3x = 15
e) 7x = -21
f)2x-5=x+1
g)5x+7=4x+10
h)9x+9+3x=15
i)4x-7=8x-2
j)3x-2=4x+9
k)2(x-1)=3x+4
l)5x-3(x+2)=15

Answer 1

a) x-5 = 8

x = 8 + 5

x = 13

b) x-9 = 16

x = 16 + 9

x = 25

c) x-7 = 42

x = 42 + 7

x = 49

d) 3x = 15

x = 15/3

x = 5

e) 7x = -21

x = - 21/7

x = - 3

f) 2x - 5 = x + 1

2x - x = 1 + 5

x = 6

g) 5x + 7 = 4x + 10

5x - 4x = 10 - 7

x = 3

h) 9x + 9 + 3x = 15

12x + 9 = 15

12x = 15 - 9

12x = 6

x = 6/12

x = 1/2

i) 4x - 7 = 8x - 2

8x - 4x = - 7 + 2

4x = - 3

x = - 3/4

j) 3x - 2 = 4x + 9

4x - 3x = - 2 - 9

x = - 11

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

2x - 2 = 3x + 4

3x - 2x = - 2 - 4

x = - 6

l) 5x - 3(x+2) = 15

5x - 3x - 6 = 15

2x - 6 = 15

2x = 15 + 6

2x = 21

x = 21/2