Complete each step to solve and check each equation.
- w 9 51 2. f 14 8
w 9 51 f 14 8
w f
Check: 9 51 Check: 14 8
51 8
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Addition and Subtraction
Equations with Integers
14-2
From 9:00 P.M. to 6:00 A.M., the temperature rose
7 degrees Celsius. At 6:00 A.M., it was 2°C. What
was the temperature at 9:00 P.M.?
To find the temperature at 9:00 P.M., write and solve an equation.
Let trepresent the temperature at 9:00 P.M.
t 7 2
t 7 7 2 7
t 5
Check: 5 7 2
2 2 True
The temperature at 9:00 P.M. was 5°C.
Study these examples.
Solve: n 16 40
n 16 16 40 16
n 24
Check: 24 16 40
40 40 True
temperature rise in temperature
at 9:00 P.M. plus temperature equals at 6:00 A.M.
t 7 2
Subract 7 from both sides.
solution
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Substitute 5 for t.
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Remember:
Adding or subtracting the
same amount from both
sides of a true equation
results in a true statement.
Solve: h 11 4 9
h 11 4 9
h 15 9
h 15 15 9 15
h 6
Check: 6 11 4 9
9 9 True
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