Example

Solving m=x2y3m = \frac{x-2}{y-3} for yy

Solve the rational equation m=x2y3m = \frac{x-2}{y-3} for the variable yy by applying the strategy for solving equations with rational expressions. This formula is based on the slope formula, where mm represents the slope of a line passing through the points (2,3)(2, 3) and (x,y)(x, y).

Step 1 — Identify restricted values. The variable yy appears in the denominator (y3)(y - 3), so y3y \neq 3.

Step 2 — Clear the fractions. The LCD is (y3)(y - 3). Multiply both sides by (y3)(y - 3):

(y3)m=(y3)x2y3(y - 3) \cdot m = (y - 3) \cdot \frac{x - 2}{y - 3}

Step 3 — Simplify. On the right, the (y3)(y - 3) factors cancel:

m(y3)=x2m(y - 3) = x - 2

Distribute mm on the left:

my3m=x2my - 3m = x - 2

Step 4 — Isolate the term with yy. Add 3m3m to both sides:

my=x2+3mmy = x - 2 + 3m

Step 5 — Divide both sides by mm to isolate yy:

y=x2+3mmy = \frac{x - 2 + 3m}{m}

This example is more involved than the previous one because the target variable yy appears inside a binomial denominator (y3)(y - 3). After clearing the fraction by multiplying both sides by the LCD, distributing is required to separate the yy-term from the constant. Collecting the yy-term on one side and then dividing by its coefficient mm produces the final result.

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Updated 2026-04-21

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