Question

1)determine o valor de cada letra. a)x + 8 = 20 b)y - 21 =42 c)a - 171 = 868 d)7d - 28 e)c : 9 = 7 f)4n = 42 g)x + 21 = 6 h)9 = x + 17 i)6 x = 84 j)x - 7 = 77 k) - 5 = y - 8 l)a - 10 = -13 m) -3 x = 27 n)5 x y = 0

Answer 1

Resposta:

1) a) x+8=20

×=20-8

×=12.

b)y-21=42

y=42+21

y=63

c)a-171=868

a=868+171

a=1039

d)7d-28

d=-28/7

d=-4

e)c÷9=7

c=7÷-9

c=-2

f)4n=42

n=42/4

n=10,5

g)x+21=6

×=6-21

×=-15/6

×=-2,5

h)9=×+17

×=17-9

×=8

i)6×=24

×=24/6

×=4

j)×-7=77

×=77+7

×=84

k)-5=y-8

y=-8+5

y=-3

l)a-10=-13

a=-13+10

a=-3

m)-3×=27

×=27+3

×=30.

a letra n) eu n sei

Answer 2

a)x + 8 = 20

x=20–8=12

b)y - 21 =42

y=42+21=63

c)a - 171 = 868

a=868+171=1039

d)7d - 28=0

7d=28

d=28/7

d=4

e)c : 9 = 7

c=7.9

c=63

f)4n = 42

n=42/4

n=21/2

g)x + 21 = 6

x=6-21

x=-15

h)9 = x + 17

x=9–17

x=–8

i)6 x = 84

x=84/6

x=14

j)x - 7 = 77

x=77+7

x=84

k) - 5 = y - 8

y=8–5

y=3

l)a - 10 = -13

a=10–13

a=–3

m) -3 x = 27 ×(–1)

3x=–27

x=–27/3

x=–9

n)5 x y = 0

xy=0/5

xy=0