Change the equation from standard form to slope-intercept form by solving for y.

11x - 8y = -48
Bob's work:
-8y = -59x
y = 7.375
Bill's work:
-8y = -11x - 48
y = 11/8x + 6
Bud's work: -8y = -11x - 48
y = -11x + 6
Who solved for y correctly?
A. None of them are correct
B. Bob
C. Bill
D. Bud

1 answer

To determine who solved for y correctly from the equation \( 11x - 8y = -48 \), we need to convert it to slope-intercept form \( y = mx + b \).

Starting with the given equation: \[ 11x - 8y = -48 \]

We'll first isolate the term involving y: \[ -8y = -11x - 48 \]

Now, dividing every term by -8: \[ y = \frac{11}{8}x + 6 \]

Now, let's compare this with what each person has done:

  • Bob's work: He arrived at \(-8y = -59x\) which is incorrect and doesn't help in solving for \(y\), and finally stated \(y = 7.375\), which is not correct.

  • Bill's work: He correctly got to \(-8y = -11x - 48\), and then correctly computed the slope-intercept form as \(y = \frac{11}{8}x + 6\), which is correct.

  • Bud's work: He also obtained \(-8y = -11x - 48\), but then incorrectly stated \(y = -11x + 6\), which is incorrect because he did not divide by -8 correctly.

The correct transformation gives: \[ y = \frac{11}{8}x + 6 \]

Thus, the correct answer is:

C. Bill