Addition and Subtraction Equations
Danny and Carly like to work on jigsaw puzzles. Danny has two puzzles. If together they have 9 puzzles, then we can use the equation x + 2 = 9 to determine how many puzzles Carly has. How many puzzles does Carly have?
7 puzzle
3x = 210
x=70
x ≤ 3; x = 3
Is the inequality a solution or not a solution.
solution
25 = a/5
a=125
What is the answer to an addition problem called?
Sum
12 = x − 24
x=36
3.5x = 14.7
x=4.2
y < 7.8; y = 8
Is the inequality a solution or not a solution.
no solution
z/16 = 8
z=128
What is the answer to an subtraction problem called?
difference
The equation l – 12.5 = 48.6 can be used to find the original length l in centimeters of a wire before it was cut. What was the original length of the wire?
61.1 centimeters
23.8 = 3.5b
b=6.8
q ≥ 0.6; q = 0.23
Is the inequality a solution or not a solution.
no solution
a/14 = 6.8
a=95.2
What is the answer to an multiplication problem called?
product
The price tag on a shirt says $21.50. The final cost of the shirt, including sales tax, is $23.22. The equation 21.50 + t = 23.22 can be used to find the amount of sales tax t in dollars. What is the sales tax?
$1.72
Estella buys 1.8 pounds of walnuts for a total of $5.04. She solves the equation 1.8p = 5.04 to find the price p in dollars of one pound of walnuts. What does one pound of walnuts cost?
$2.80
b < 2 3/4 ; b = 2/3
solution
1/4 = 3/5s
s=5/12
What is the answer to an division problem called?
quotient
m − 2 3/4 = 6 1/2
m=9 1/4
Carlos bought 5 tickets to a play for a total of $20. The equation 5c = 20 can be used to find the cost c in dollars of each ticket. How much does each ticket cost?
$4
The inequality w ≥ 3.2 represents the weight of each pumpkin, in pounds, that is allowed to be picked to be sold. The weights of pumpkins are listed. How many pumpkins can be sold? Which pumpkins can be sold? 3.18 lb, 4 lb, 3.2 lb, 3.4 lb, 3.15 lb
3 weights: 4 lb, 3.2 lb, and 3.4 lb
2/5w = 40
w=100
Pairs of mathematical operations that reverse or "undo" each other, acting as opposites to return a value to its original state.
Inverse Operations