Solve 8x + 7y = 15 for y.
Ay is 15 plus 8x, over 7
By is 15 minus 8x, over 7
Cy is 8x minus 15, over 7
Dy is 15 minus 8x, over 8
Answer & Solution
Correct answer: B. y is 15 minus 8x, over 7
1. Treat y as the variable to isolate and everything else as a known quantity.
2. Subtract 8x from both sides to get 7y equal to 15 minus 8x.
3. Divide both sides by 7 to get y equal to 15 minus 8x, all over 7.
4. Adding 8x instead of subtracting it flips the sign and gives a different line.
_Source: OpenStax Intermediate Algebra (CC BY 4.0), Ch 2 "Solving Linear Equations", section 2.3 Solve a Formula for a Specific Variable_
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