Solving Equations (1-step)
x + 15 = 18
x = 3
5x + 7 = 32
x = 5
Write as an expression:
- a number plus five is twenty
- a number subtract four is zero
x + 5 = 20
x - 4 = 0
Substitute x=3 into the expression. Evaluate.
x + 4
(3) + 4 = 7
Verify the solution x = 9 into the equation. Is the solution true or false?
x + 3 = 12
True!
x - 5 = 6
x = 11
x/2 - 11 = 1
x = 24
Write as an equation:
- a number times six is twelve
- a number divided by four is eight
6x = 12
x/4 = 8
Substitute x = 5 into the following expressions and evaluate.
12 + x
x - 4
12 + (5) = 17
(5) - 4 = 1
Verify the solution x = 6 in the following equations.
4 + x = 13
x - 5 = 1
False
True!
3x = 24
x = 8
-4 + 2x = 28
-3 + x/2 = 8
x = 16
x = 22
Write as an equation: A taxi charges a $4 flat fee plus $2.50 for every kilometre travelled.
2.50d + 4 = c
Substitute the solution x = 15 into the expression and evaluate.
4x + 28
4(15) + 28 = 88
Verify the solution x = 11 into the equation.
3x + 15 = 48
True!
x/7 = 8
x = 56
3x - 18 = 2x + 44
x = 62
Write as an expression: A plant is 12 cm tall and grows 2.8 cm each week.
2.8x + 12
Substitute the solution x = 18 into the expression and evaluate.
x/6 - 8
(18)/6 - 8 = -6
Verify the solution x = 12 into the equation.
x/3 - 2 = -1
False,
12/3 - 2 = 2
10x = 90
x/15 = 4
x = 9
x = 60
12/x = 2/3
x = 18
Write as an expression: “Write a relation for the total length of an octagon if each of its sides has length n, and then subtract 1 from that total.”
8n - 1
Substitute x = 26 into the following expressions and evaluate.
10x - 13
x/2 + 92
10(23) + 20 = 247
(26)/2 + 91 = 105
Verify the solution x = 25 into each equation. Is the solution true or false for each equation?
3x + 25 = 125
2x/10 - 17 = -12
False
True