Algebra 22.3

Pinkston

SAT Question

If x + 3 = 13, what does x – 5 equal?A. 5B. 8C. 10D. 11E. 15

10

5 5

x

So x

Literal Equation: An equation that contains more

than one variable.

Formula: A literal equation that is a rule for giving specific

calculations.

Example 1: Solve W = EI for I

W EI

E E

WI

E

Example 2: Solve for b.

5( 20)

2A b

550

2A b

(2) (2)5

502

(2)A b

2 5 100A b

2 5 100A b 100 100

2 100 5A b 5 5

2 100

5

Ab

Example 3: Solve for b.

1(2) 2

2A bh

1

2A bh

2A bhh h

2Ab

h

3 5Q r p

Example 4: Solve for p.

3 5Q r p 3 3r r

5 53

5

Q rp

Example 5: Solve A = P + Prt for P.

A = P + Prt

A = P(1 + rt)1+ rt1+ rt

1

AP

rt

Example 6: Solve T = Q + Qiy for Q.

T = Q + Qiy

T = Q(1 + iy)1+ iy1+ iy

1

TQ

iy

Classwork:

2-24 even/72

Get ready for a “Small Quiz” to be written

on your grade sheet.

Solve:A twenty foot cord is divided into two parts. One part is 2 less than twice the other. What is the measurement of each part?

Quiz. Copy the problem and write the answer.

Put your grade paper on the front of your row, quiz side down.

THE END