Question

2(3b+6) =78 : Answer is 11

-2(6c-3) = -72 : Answer is 6.5

Check left Side of both equations

Answer 1

1. b = 11
2. c = 6.5

Explanation:

1) 2(3b + 6) = 78, value of b?

→ 2(3b + 6) = 78

→ 6b + 12 = 78

→ 6b = 78 - 12

→ 6b = 66

→ b = 66/6

→ [ b = 11 ]

Hence, the value of b is 11.

2) -2(6c - 3) = -72, value of c?

→ -2(6c - 3) = -72

→ -12c + 6 = -72

→ -12c = -72 - 6

→ -12c = -78

→ c = (-78)/(-12)

→ c = 78/12

→ [ c = 6.5 ]

Hence, the value of c is 6.5.

Answer 2

Solve each equation in steps:

• 2(3b + 6) =78 Given
• 3b + 6 = 39 Divide both sides by 2
• 3b = 33 Subtract 6 from both sides
• b = 33/3 Divide by 3
• b = 11 Answer

• -2(6c - 3) = -72 Given
• 6c - 3 = 36 Divide both sides by - 2
• 6c = 39 Add 3 to both sides
• c = 39/6 Divide by 6
• c = 6.5 Answer