Homework for 3-8Homework for 3-8p.187 2, 5, 10, 11, 15, 18, 20, 26, 27, 32, 34

3-8 Rewrite Equations & 3-8 Rewrite Equations & FormulasFormulasObjective: rewrite equations and formulas, solve for variables.

Colby says, “A literal equation is an equation in which there are no numbers, only letters.”

Literal EquationsLiteral Equations

2x + 5 = 11 and 6x + 3 = 15 have the general form ax + b = c.

ax + b = c is a literal equation. Solving a literal equation can

sometimes make solving an equation of the same form easier.

Tip: Circle the letter(or variable) that you are solving for.

PracticePracticeSolve p + qx for x.

x = (r-p)/qNow solve 3 + 5x = -7

x = -2Write -2x + 3y = 6 so that y is a

function of x. y = (2/3)x + 2

For a rectangle, A = lw.

Solve the formula for the length.

L = A / w

Use the rewritten formula to find the length of this rectangle.

L= 27cm.

13 cm.A = 351 cm2

Irina deposited $650 in a savings account. After two years her account balance was $682.50. Find the rate of interest for the two years. Use the formula A = P(1 + rt), where A is the account balance, P is principal, r is rate, and t is time. Rewrite the formula to isolate r and then solve.

r = (A – P)/ Ptr = 2.5%