Question

Solve the following equation if d = -2. If necessary, round to the nearest tenth.⁣ 2/3(6c+9d)+3/4(8c-16d)=-18

Answer 1

2/3 (6c + 9d) + 3/4 (8c - 16d) = -18

We are solving for c when d = -2

Substitute D: 2/3 (6c + 9(-2)) + 3/4 (8c - 16(-2)) = -18

Solve parentheses, multiply fraction with parentheses: 2/3 (6c -18) + 3/4 (8c + 32) = -18

Combine like terms: 4c - 12 + 6c + 24 = -18

Subtract 12 from both sides: 10c + 12 = -18

Divide by 10: 10c = -30

ANSWER: c = -3

Answer 2

• c = - 3

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Simplify the equation by distribution, then substitute the value of d and solve for c:

• 2/3(6c + 9d) + 3/4(8c - 16d) = - 18
• 2/3(6c) + 2/3(9d) + 3/4(8c) - 3/4(16d) = - 18
• 4c + 6d + 6c - 12d = - 18
• 10c - 6d = - 18
• 10c - 6(-2) = - 18
• 10c + 12 = - 18
• 10c = - 12 - 18
• 10c = - 30
• c = - 3