Kecia spent $131 on shirts. fancy shirts cost $28 and plain shirts cost $15. if she bought a total of 7 shirts, how many of each kind did she buy

STEP-BY-STEP SOLUTION:

Let's solve this problem step-by-step.

We will be using simultaneous equations to solve this problem.

Let's first establish the equations we will be using as displayed below:

Let x = fancy shirts

Let y = plain shirts

Equation No. 1 -

x + y = 7

Equation No. 2 -

28x + 15y = 131

To begin with, let's make ( x ) the subject in the first equation as displayed below:

Equation No. 1 -

x + y = 7

x = 7 - y

Now let's substitute the equation for ( x ) from the first equation into the second equation as displayed below:

Equation No. 2 -

28x + 15y = 131

28 ( 7 - y ) + 15y = 131

196 - 28y + 15y = 131

- 28y + 15y = 131 - 196

- 13y = - 65

y = - 65 / - 13

y = 5

From here, let's substitute the value of ( y ) from the second equation into the first equation as displayed below:

Equation No. 1 -

x = 7 - y

x = 7 - ( 5 )

x = 2

ANSWER:

x = 2

y = 5

Therefore, Kecia bought a total of 2 fancy shirts and 5 plain shirts.