Question

Determine o valor da incógnita nas equações: a) 3m - 1 = 17

b) 45 = 3k + 3

c) 4v - 6 + 2v = v - 7

d) 2a - 5 x (3 - a) = 0

e) 45 = 15 - 3 x (2x + 6) = 0

f) 2 x (x + 5) - 3 x (2x + 6) = 0

g) 30 = 10 x (5 - h) + 4h

h) 4w - 8w + 9 = w - 5

i) 12 - 3 x (a - 15) = 10 + 5 x (5 - a)

j) 2p + 5 - 10p = 45

Answer 1

a) 3m - 1 = 17
3m=17+1
3m=18
m=18/3
m=6

b) 45 = 3k + 3
3k=45-3
3k=42
x=42/3
x=14

c) 4v - 6 + 2v = v - 7
4v + 2v - v = -7 + 6
5v=-1
v=-1/5

d) 2a - 5 x (3 - a) = 0
2a-15 +5a=0
7a = 15
a=15/7

e) 45 = 15 - 3 x (2x + 6)
45 = 15 -6x-18
6x=15-18-45
6x=-48
x=-48/6
x=-8

f) 2 x (x + 5) - 3 x (2x + 6) = 0
2x + 10 - 6x - 18 = 0
-4x=18-10
-4x=8
x=8/(-4)
x=-2

g) 30 = 10 x (5 - h) + 4h
30= 50 - 10h + 4h
-10h+4h=30-50
-6h = - 20
h=20/(-6) (simplificar por 2)
h= -10/3

h) 4w - 8w + 9 = w - 5
-4w - w = -5 - 9
-5w = -14
w = -14 / (-5)
w = 14/5

i) 12 - 3 x (a - 15) = 10 + 5 x (5 - a)
12 - 3a + 45 = 10 + 25 - 5a
-3a + 5a = 10 + 25 - 12 - 45
2a = -22
a = -22/2
a= -11

j) 2p + 5 - 10p = 45
-8p = 45 - 5
-8p = 40
p = 40/(-8)
p=-5

Answer 2

Resposta:

a) 3m - 1 = 17

3m=17+1

3m=18

m=18/3

m=6

b) 45 = 3k + 3

3k=45-3

3k=42

x=42/3

x=14

c) 4v - 6 + 2v = v - 7

4v + 2v - v = -7 + 6

5v=-1

v=-1/5

d) 2a - 5 x (3 - a) = 0

2a-15 +5a=0

7a = 15

a=15/7

e) 45 = 15 - 3 x (2x + 6)

45 = 15 -6x-18

6x=15-18-45

6x=-48

x=-48/6

x=-8

f) 2 x (x + 5) - 3 x (2x + 6) = 0

2x + 10 - 6x - 18 = 0

-4x=18-10

-4x=8

x=8/(-4)

x=-2

g) 30 = 10 x (5 - h) + 4h

30= 50 - 10h + 4h

-10h+4h=30-50

-6h = - 20

h=20/(-6) (simplificar por 2)

h= -10/3

h) 4w - 8w + 9 = w - 5

-4w - w = -5 - 9

-5w = -14

w = -14 / (-5)

w = 14/5

i) 12 - 3 x (a - 15) = 10 + 5 x (5 - a)

12 - 3a + 45 = 10 + 25 - 5a

-3a + 5a = 10 + 25 - 12 - 45

2a = -22

a = -22/2

a= -11

j) 2p + 5 - 10p = 45

-8p = 45 - 5

-8p = 40

p = 40/(-8)

p=-5