Final answer:
The next step for Leah to write an equivalent equation that solves for y is to add 4y to both sides of the equation.
Step-by-step explanation:
The next step for Leah to write an equivalent equation that solves for y is to add 4y to both sides of the equation. This will isolate the variable y on one side of the equation. The new equation will be:
3x + 4y - 8 = 3x
Now she can solve for y by performing any additional steps necessary.