Three fourths a number plus 8 is 20 less than the number

Equation:  

Solve for n:  n = 112

Step-by-step explanation:

To first set up the equation, you need to look at the verbal description and translate into numbers and operations:

'three fourths a number' =  

'plus 8' = + 8

'is' =

'20 less' = - 20

'the number' = n

Put the expressions together:

'three fourths a number plus 8':  

'20 less than the number': n - 20

Set them equal to each other and solve:

Add 20 to both sides:

Subtract from both sides:

Multiply both sides by :

Solve for n:  n = 112

he earned 78.75 in interest.

step-by-step explanation: