Ajuda em trabalho de matemática :

1) Resolva as equações :

a) 2x = -8
b) x-5 = 15
c) x+4 = 8
d) 3y + 1 = 10
e) 12x - 10 = 5x + 11
f) 8x - 9 = 2x + 11
g) 10 -4x = 9 -2x

2) Resolva aplicando a propriedade distributiva :

a) 2(7x+2)+12(x+1) = 2
b) 4.(x-4)-2(3x+4) = 6
c) 2.(x+5) = -4
d) 5(y-3) = 2y + 3
e) 5. (3x-5) -2 (x-2) = 70
f) -8. (x-1) = -16

1

Respostas

A melhor resposta!
2013-11-22T00:58:58-02:00
1 )
2x = -8
x=-8/2
x=-4

b

x-5 = 15
x=15+5
x=20

c )

x+4 = 8
x=8-4
x=4

d) 3y + 1 = 10
3y=10-1
3y=9
y=9/3
y=3

e) 12x - 10 = 5x + 11
12x-5x=11+10
7x=21
x=21/7
x=3

f) 8x - 9 = 2x + 11
8x-2x=11+9
6x=20
x=20/6
x=10/3

g) 10 -4x = 9 -2x
-4x+2x=9-10
-2x=-1 (-1)
2x=1
x=1/2

2 )

a) 2(7x+2)+12(x+1) = 2
14x+4+12x+12=2
14x+12x=2-4-12
2x=-14
x=-14/2
x=-7

b) 4.(x-4)-2(3x+4) = 6
4x-16-6x-8=6
4x-6x=6+16+8
-2x=30 (-1)
2x=-30
x=-30/2
x=-15

c) 2.(x+5) = -4
2x+10=-4
2x=-4-10
2x=-14
x=-14/2
x=-7

d) 5(y-3) = 2y + 3
5y-15=2y+3
5y-2y=3+15
3y=18
y=18/3
y=6
e )

5. (3x-5) -2 (x-2) = 70
15x-25-2x+4=70
15x-2x=70+25-4
14x=91
x=91/14

f )

-8. (x-1) = -16
-8x+8=-16
-8x=-16-8 (-1)
8x=16+8
8x=24
x=24/8
x=3
.
2 5 2