2. What is Algebra?
A clown was carrying a handful of balloons.
Along came the wind and blew 8 away, leaving
him only with 9. How many did he start with?
Algebra takes real life problems and puts
them into math so we can solve them.
x-8 = 9
The goal in Algebra is to find out the
unknown!
3. A scale has 20 pennies on one side . On the other side is 6 pennies
and an unknown amount of pennies. Both sides equal the same
weight.
20 = 6 + x
20 6 pennies
pennies + ? pennies
5. What is Algebra?
A clown had 17 balloons. Along came the wind
and blew 8 away, leaving him only with 9.
The goal in Algebra is
to find out the
unknown!
6. -Different signs subtract numbers
-Always keep the sign of the larger number
when subtracting and adding
-3 + 7 = 4
- - - +++ +++ +
26. Key Terms
• product multiply
• squared times itself
• sum add
• difference subtract
• half divide by 2 or ½
• quotient divide
• decreased subtract
27. Guided Practice
six more than the square of four is twenty two=
4² + 6 = 22
5x – 1 = 7
one less than five times a number equals seven
the quotient of a twelve and four plus a number
12 ÷ 4 + n
28. Algebra Rules
1. What you do to one side you must do to the other. This keeps
them equal.
2. You must get the variable by itself to find out what number
value it equals.
29. Guided Practice
-4 = x + 2 ½ n -4 = 9-2
-2 -2 ½ n -4 = 7
x = -6 +4 +4
½ n = 11
3 + 2n = 43 2( ½ n) = 11(2)
-3 -3 n = 22
2n = 40
2 2
n = 20
31. Guided Practice
3(n) – 2(4) + 16 / x if x = 4
3(4) – 2(4) + 16 / 4
12 – 8 + 16 / 4
12 – 8 + 4
12 – 12
0
32. Guided Practice
b³c + bc + 2b² if b = 3; c = 4
(3) ³(4) + (3)(4) + 2(3) ²
9(4) + (3)(4) + 2(9)
36 + 12 + 18
66
33. Key Terms
• expression
– a way to represent spoken information about an
unknown number:
“a number plus 3” = n + 3
• equation
– shows that two quantities are equal
• inequality
– uses symbols < and > to show “greater than” and
“less than”