An equation is a mathematical statement that two expressions have the same value, which are separated by an equal sign, “=”.
To solve one step equations, we should know about inverse operations.
Example 1 :
Eighteen more than the number n is 125. What is the value of n?
Solution :
Eighteen more than the number n = 125
18 + n = 125
Subtract 18 on both sides.
n = 125-18
n = 107
Example 2 :
Jim’s three fish tanks contain an equal amount of fish. If Jim has a total of 27 fish, how many fish are in each tank?
Solution :
Number of fish tank Jim has = 3
Let x be the number of fishes in each tank.
Total number of fishes = 24
3x = 27
Divide by 3 on both sides
x = 27/3
x = 9
Example 3 :
Steven went to the store and bought five sweatshirts. He spent $45. What was the price of each shirt?
Solution :
Number of sweat shirts he bought = 5
Let x be the cost of each sweat shirt.
Cost spent = $45
5x = 45
Divide by 5 on both sides.
x = 45/5
x = 9
Example 4 :
How many boxes of envelopes can you buy with $12, if one box costs $3?
Solution :
Let x be the number of boxes.
Cost of one box = $3
Cost spent = $12
3x = 12
Divide by 3 on both sides.
x = 12/3
x = 4
Example 5 :
At a restaurant, Bill and his four friends decided to divide the bill evenly. If each person paid $12, what was the total bill?
Solution :
Bill + his four friends = 5 persons
Each friend is paying = $12
Total bill = 5(12)
= $60
Example 6 :
Last Saturday, Allyson had $38. For her birthday she received more money. She now has $90. How much money did she receive?
Solution :
Let x be the amount she has received.
The amount that she has = $90
x + 38 = $90
Subtract 38 on both sides.
x = 90 - 38
x = $52
So, he has received $52.
Example 7 :
The sum of three fourths of the number a and 24 is negative 9. What is the value of a?
Solution :
(3/4) of a + 24 = -9
3a/4 + 24 = -9
3a/4 = -9-24
3a/4 = -33
Multiply by 4 on both sides.
3a = -33(4)
Divide by 3 on both sides, we get
a = -11(4)
a = -44
Example 8 :
Twenty is 7 less than twice the number w. What is the value of w?
Solution :
Twice the number w = 2w
20 = 2w-7
Add 7 on both sides.
20+7 = 2w
2w = 27
Divide by 2 on both sides, we get
w = 27/2
w = 13.5
Example 9 :
-11+ x = 9
Given the above equation, what is the value of 20-(11-x) ?
Solution :
-11+ x = 9
Add 11 on both sides
x = 9 + 11
x = 20
20-(11-x) :
By applying the value of x in the given expression.
= 20 - (11 - 20)
= 20 - (-9)
= 20+9
= 29
Example 10 :
Two and three fifths of a number equals -26. What is the number?
Solution :
Let x be the required number.
2 3/5 of x = -26
13/5 of x = -26
13x/5 = -26
Multiply by 5 on both sides, we get
13x = -26(5)
Divide by 13 on both sides.
x = -26(5)/13
x = -2(5)
x = -10
May 21, 24 08:51 PM
May 21, 24 08:51 AM
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