Monica built a porch that contained 2 different colors of bricks to create a pattern. she purchased the red bricks for $7 each and the gray bricks for $4 each. write a system to find out how many red bricks monica purchased if she spent $193 on 40 bricks?

a. what is the system that models this situation?
equation #1:
equation #2:

b. how many red bricks did monica purchase?

a.

b. 11 red bricks

Step-by-step explanation:

Let x be the number of red bricks and y be the number of grey bricks.

1. Monica purchased 40 bricks, so

2.  If she purchased the red bricks for $7 each, then x red bricks cost $7x. If the gray bricks are for $4 each, then y bricks cost $4y. In total, all bricks cost $(7x + 4y) that is $193. Hence,

a. The system of two equations is

b. From the first equation:

Substitute it into the second equation:

Monica purshased 11 red bricks and 29 grey bricks.

  the correct choice is marked

step-by-step explanation:

the first two graphs show multiple turning points. the last graphs matches the description in every detail.

yes.. it's proven to be 36.