Math 025 Unit 5 Section 6.7

A literal equation is an equation that contains more than one variable. Examples: 2x + 3y = 6 4w – 2x + z = 7 Many formulas are literal equations. A = l w V = lwh To solve a literal equation, use equation solving techniques to rearrange the equation until the desired variable is alone on one side of the equation.

Objective: To solve a literal equation Solve for y: 3x – 4y = 12 Subtract 3x from both sides -4y = 12 – 3x Divide both sides by -4 y = 12 – 3x - 4 The answer can be rearranged if desired y = 3x – 12 4

Objective: To solve a literal equation Solve for x: 5x – 2y = 10 Add 2y to both sides 5x = 10 + 2y Divide both sides by 5 x = 10 + 2y 5 The answer can be rearranged if desired 2y x = + 2 5

Objective: To solve a literal equation Solve for R: I = Multiply the equation by (R + r) to clear any fractions E (R + r) R + r IR + Ir = E Subtract Ir from both sides IR = E – Ir Divide both sides by I R = E – Ir I

Objective: To solve a literal equation Solve for c: L = a(1 + c) Simplify the right side by multiplying L = a + ac Subtract a from both sides L – a = ac Divide both sides by a c = L – a a

Objective: To solve a literal equation Solve for C: S = C – rC Factor the right side S = C(1 – r) Divide both sides by (1 – r) C = S 1 – r