6) Qual é o número cuja diferença entre a sua terça parte e a...

1.

x + 2x = 72
3x = 72
x = 72/3
x = 24

2.

3x + 15 = 39
3x = 39 - 15
3x = 24
x = 24/3
x = 8

3.

x + (1/4)x = 60
(4/4)x + (1/4)x = 60
(5/4)x = 60
x = 60/(5/4)
x = 60×(4/5)
x = 48

4.

(2/3)x - (1/2)x = 10
(4/6)x - (3/6)x = 10
(1/6)x = 10
x = 10/(1/6)
x = 10×(6/1)
x = 60

5.

A-5 = P | A = P+5
A+P = 35
P+5+P = 35
2P = 35 - 5
P = 30/2
P = 15

A = 15 + 5
A = 20

6.

L - 16 = C | L = C + 16
L + C = 124
C+16+C = 124
2C = 124-16
C = 108/2
C = 54

L = 54 + 16
L = 70

7.

x + y = 138
y = x + 2

x + (x + 2) = 138
2x = 138-2
x = 136/2
x = 68

y = 68+2
y = 70

8.

x + y = 73
y = x + 1

x + (x + 1) = 73
2x = 73-1
x = 72/2
x = 36

y = 36+1
y = 37

9.

x + y + z + k = 150
y = x + 1 = 36+1 = 37
z = x + 2 = 36+2 = 38
k = x + 3 = 36+3 = 39

x + (x+1) + (x+2) + (x+3) = 150
4x = 150-1-2-3
x = 144/4
x = 36

36+37+38+39=150

10.

x > y
x + y = 103 | x = 103-y
x - y = 23
103 - y - y = 23
-2y = 23-103
y = -80/-2
y = 40

x = 103-40 = 63

Espero ter ajudado!​