1. Steps for Solving Equations!
Distribute
Combine Like Terms on each side of =
Move variables to one side of = and constants (numbers) to the other side
Undo addition or subtraction
Undo multiplication or division
Simplify

2. Objective- To solve equations in the form ax + b = cx + d.
14k + 20 = 21k - 43
-14k k
20 = 7k - 43
63 = 7k
9 = k

3. Solve.
x x = 2x
2.05x = 2x
-2x x
0.05x =
x = -20,000

4. Solve.
- 2y = - 6y
+2y y
11 = - 4y
= y

5. When do they cost the same? 250 + .01n = 70 + .03n - .01n - .01n
An Easier Way of Doing Printing Problem!
Let n = number copies
Let C = total charge
Acme
Best
C = n
C = n
When do they cost the same?
n = n
- .01n n
= n
They cost the
same at
9000 copies.
180 = .02n
= n

6. Problem
In 1990, the population of El Paso was
515,000 and increasing at 9000 people
per year. Milwaukee was 628,000 and
decreasing at 800 people per year. When will they be the same?
Let n = number of years
Let P = population
El Paso
Milwaukee
P = 515, n
P = 628, n

7. Let n = number of years
Let P = population
El Paso
Milwaukee
P = 515, n
P = 628, n
515, n = 628, n
+ 800n n
515, n = 628,000
-515, ,000
9800n = 113,000
n years

8. Tree Problem
A beech tree is 8 ft. tall and grows
ft. per year. A maple tree is 3 ft.
tall and grows 1 foot per year. When
will the trees be the same height?
Let x = number of years
Let h = height of tree
Beech tree
Maple tree
h = x
h = 3 + x

9. When is maple taller than beech?
Let x = number of years
Let h = height of tree
Beech tree
Maple tree
h = x
h = 3 + x
x = x
- 0.5x x
8 = x
5 = 0.5x
x = 10 years
10 = x