Solving equations
Formulas
Definitions
Simplifying expressions
Rewriting expressions
100
If x = 3
21 + x =
21 + 3 = 24
100
Write a formula for this shape...
x + x + (x + 2)
= 3x + 2
100
What does simplify mean?
Means to make an equation more simple (shorter).
100
2 x 5a =
10a
100
A number with 4 subtracted from it.
x - 4
200
If x = 5
5x
5x
= 5 x 5
= 25
200
Write a simplified equation for this shape...
(x + 4) + x + (x + 4) + x
= 4x + 8
200
What does substitution mean?
If x = 5 for example, you replace the x in the equation with the number.
200
3 x r =
3r
200
2 times a number
2x
300
If x = 8
3x + 4 =
(3 x 8 ) + 4
= 24 + 4
= 28
300
Write a simplified formula for this shape...
(y + 3) + y + (y + 6) + y
= 4y + 9
300
What does symbol mean?
These are letters such as x and y that represent a number.
300
1 x g =
g
300
A number divided by 8
x / 8
400
If x = 9, y = 7
2x - y =
(2 x 9) - 7
= 11
400
A rectangle has four sides. The longer side is twice as long as the shorter side. What is the formula for the perimeter of this shape?
2x + x + 2x + x
= 6x
Where 6 = the length of the short side.
400
Define Unlike terms
terms that cannot be combined e.g., x + y cannot become xy
400
3 x 2a x 5 =
30a
400
Five plus a number divided by 9
(5+x)/9
500
If x = 8, y = 3, z = 5
xy + yz =
(8 x 3) + (3 x 5)
= 24 + 15
= 39
500
A triangle has 3 sides. Two of the sides are the same length. The other side is three times longer than the shorter sides. What is a formula for its perimeter?
3x + x + x
= 5x
500
Define Formula
A rule to explain how to calculate something.
500
4 x 3a x 5b =
60ab
500
Two times a number plus 6, then divided by 8
(2x + 6) /8