Omar was paid on friday. on saturday he spent 1/4 of his pay and on sunday he bought a new smartphone with 2/3 of the remainder. after spending $15 on dinner, omar had 20% of his pay left. what was omar paid on friday? explain how to set up the equation to solve the problem

Friday: 300 dollars

Step-by-step explanation:

Let Omar's pay on Friday = x

Friday:     x

Saturday:  1/4 x was spent.

Sunday:  2/3 *(x - (1/4)x ) = 2/3 * (3/4x) = (2*3/(3*4)x = (6/12)x = 1/2x

Dinner:  15 dollars

Remainder = 20% x = 20/100 x = 0.2x

x - (1/4x + 1/2(x) + 15) =  0.2x          Combine like terms on the left  

x - (3/4x + 15) = 0.2x                       Remove the brackets

x - (3/4)x - 15 =  0.2x                       Combine like terms on the left

(1/4)x - 15 = 0.2x                             Change 1/4 to a decimal

0.25x - 15 = 0.2x                            Subtract 0.25x from both sides

0.25x - 0.25x - 15 = 0.2x - 0.25x  Combine

- 15 = - 0.05x                                   Divide by - 0.05

-15 /-0.05 = - 0.05 x/ 0.05

300 = x