Respuesta :

Answer:

r = 6

Step-by-step explanation:

Distribute -2 to (6 - 6r):

7r + 18 = -12 + 12r

Subtract 7r from both sides of the equation:

7r + 18 - 7r = -12 + 12r - 7r

18 = -12 + 5r

Add 12 to both sides of the equation to isolate 5r:

18 + 12 = -12 + 5r + 12

30 = 5r

Divide both sides of the equation by 5 to isolate r:

[tex]\frac{30}{5} = \frac{5r}{5}[/tex]

6 = r

To double check whether the value of r = 6 is correct, plug it into the original equation:

7r + 18 = -2(6 - 6r)

7(6) + 18 = -2[6 - 6(6)]

42 + 18 = -12 + 72

60  = 60