SOLVING ONE STEP EQUATIONS

Solve each of the following equation.

Example 1 :

x+14 = 21

Solution :

x+14 = 21

Subtract 14 on both sides.

x = 21-14

x = 7

Example 2 :

-13 = -4+h

Solution :

-13 = -4+h

Add 4 on both sides, we get

-13 + 4 = h

h = -9

Example 3 :

5y = 30

Solution :

5y = 30

Divide by 5 on both sides.

y = 30/5

y = 6

Example 4 :

x/8 = -4

Solution :

x/8 = -4

Multiply by 8 on both sides.

x = -4(8)

x = -32

Example 5 :

John buys organic almonds priced at $77 from the grocery store. How much did he pay the cashier, if he received $23 in change?

Solution :

Cost of almond = $77

Let x be the amount he has.

x - 77 = 23

x = 23 + 77

x = $100

Example 6 :

Peter and Mia participated in a quiz contest. They scored 23 points in all. If Peter scored 9 points, how many points did Mia score?

Solution :

Let x be the score of Mia.

They together scored 23 points. Peter scored 9 points.

x + 9 = 23

Subtract 9 on both sides.

x = 23-9

x = 14

So, Mia scored 14 points.

Example 7 :

Grace ran 9.7 miles less than Perry last week. Grace ran 13.8 miles. How many miles did Perry run?

Solution :

Let x be the number of miles that Perry ran.

Grace ran x-9.7 miles.

Number of miles grace ran = 13.8

x-9.7 = 13.8

x = 13.8+9.7

x = 23.5

Example 8 :

Shreya is cooking bread. The recipe calls for 5 1/6 cups of flour. She has already put in 3 9/10 cups. How many more cups does she need to put in?

Solution :

Let x be quantity of flour she need to put.

x + 3  9/10 = 5  1/6

Converting the mixed fraction into improper fraction.

x + 39/10 = 31/6

Subtract 39/10 on both sides.

x = (31/6)-(39/10)

x = (155-117)/30

x  = 38/30

x = 19/15

x = 1  4/15

Example 9 :

After paying $4.17 for a sandwich, Kali has $15.70. With how much money did she start?

Solution :

Let x be the amount he has initially.

x-4.17 = 15.70

Add 4.17 on both sides, we get

x = 15.70+4.17

x = 19.87

So, he has $19.87 initially.

Example 10 :

The product of x and three is negative-27. What is x?

Solution :

Product of x and three is = -27

3x = -27

dividing by 3 on both sides, we get

x = -27/3

x = -9