Question

Resolva as equações de primeiro grau:

a) 10x -1 (x +1)= 20

b) 2x +2 -6= 6x +12

c) x +2 (2x -18)= 114

d) 3 (x -1) +2 (x -3)= 36

e) 2 (x -2) +12x= 15x

f) 4 (2x -5) +3 (x -4)= -10

g) 7x +9 (x -5)= 147



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Answer 1

A)10x-1 (x+1)=20

10x-x-1=20

10x-x=20+1

9x=21

x=21/9

B)2x+2-6=6x+12

2x-6x=12-2+6

-4x=16

x=16÷4

x=4

C)x+2 (2x-18)=114

x+4x-36=114

x+4x=144+36

5x=180

x=180÷5

x=36

D)3 (x-1)+2 (x-3)=36

3x-3+2x-6=36

3x+2x=36+3+6

5x=45

x=45÷5

x=9

E)2 (x-2)+12x=15x

2x-4+12x=15x

2x+12x-15x=4

-x=4

-x=4 (-1)

x=4

F)4 (2x-5)+3 (x-4)=-10

8x-20+3x-12=-10

8x+3x=-10+20+12

11x=22

x=22÷11

x=2

G)7x+9 (x-5)=147

7x+9x-45=147

7x+9x=147+45

16x=192

x=192÷16

x=12