Rearranging Formulas

1
Rearranging Formulas

• Lesson 5

2
Things to Remember

• If adding or subtracting, use the zero effect to
  isolate the variable.
• If there is only one fraction, use the zero
  effect first then multiply by the denominator.
• If there is more than one fraction, use the LCM
  first, then zero effect if needed.

3

Solve the formula for w A lw
Example 1

Things to Remember Isolate the variable You
may need to multiply by the variable in the
denominator You may need to divide by the
variable in front of the variable you want to
isolate
A lw
A l
lw l

A l

w
4

Solve the formula for h A
Example 2
1 2
bh

Things to Remember Isolate the variable You
may need to multiply by the variable in the
denominator You may need to divide by the
variable in front of the variable you want to
isolate
1 2
A bh
(
)
1 2

2(A)
2
bh

bh
2A
2A b
bh b

2A b
h

5

Solve the formula for a g a w
Example 3

Things to Remember Isolate the variable Use the
zero effect You may need to multiply by the
variable in the denominator You may need to
divide by the variable in front of the variable
you want to isolate
g a w
g - w a w - w
g - w a
6

Solve the formula for t W R Ht
Example 4

Things to Remember Isolate the variable Use the
zero effect You may need to multiply by the
variable in the denominator You may need to
divide by the variable in front of the variable
you want to isolate
W R Ht
W - R R - R Ht
W - R Ht
W - R H
Ht H

W - R H

t
7

Solve the formula for u v u at
YOU TRY

Things to Remember Isolate the variable Use the
zero effect You may need to multiply by the
variable in the denominator You may need to
divide by the variable in front of the variable
you want to isolate
8

Solve the formula for u v u at
SOLUTION

Things to Remember Isolate the variable Use the
zero effect You may need to multiply by the
variable in the denominator You may need to
divide by the variable in front of the variable
you want to isolate
v u at
v - at u at - at
v - at u
9

Solve the formula for R C F Rn
YOU TRY

Things to Remember Isolate the variable Use the
zero effect You may need to multiply by the
variable in the denominator You may need to
divide by the variable in front of the variable
you want to isolate
10

Solve the formula for R C F Rn
SOLUTION

Things to Remember Isolate the variable Use the
zero effect You may need to multiply by the
variable in the denominator You may need to
divide by the variable in front of the variable
you want to isolate
C F Rn
C - F F - F Rn
C - F Rn
C - F n
Rn n

C - F n
R

11

Solve the formula for u s ut at2
YOU TRY
1 2

Things to Remember Isolate the variable Use the
zero effect You may need to multiply by the
variable in the denominator You may need to
divide by the variable in front of the variable
you want to isolate
12

Solve the formula for u s ut at2
SOLUTION
1 2

Things to Remember Isolate the variable Use the
zero effect You may need to multiply by the
variable in the denominator You may need to
divide by the variable in front of the variable
you want to isolate
1 2
s ut at2
1 2
2(s) 2(ut) 2( at2)
2s 2ut at2
2s - at2 2ut at2 - at2
2s - at2 2ut
s t
2s - at2 2t
2ut 2t
at 2
-


u

13
Class work

• Complete Lesson 4(3) and pass in
• Copy down notes and examples to Lesson 5
• Complete Lesson 5 worksheet