5x - 2y + 1z = 8 ⇒ 5x - 2y + 1z = 8
-9x + 2y + 2z = 5 ⇒ -9x + 2y + 2z = 5
-9x - 2y - 5z = 4 -4x + 3z = 13
5x - 2y + 1z = 8
-9x + 2y + 2z = 5 ⇒ -9x + 2y + 2z = 5
-9z - 2y - 5z = 4 ⇒ -9x - 2y - 5z = 4
-18x - 3z = 9
-4x + 3z = 13
-18x - 3z = 9
-22x = 22
-22 -22
x = -1
-18x - 3z = 9
-18(-1) - 3z = 9
18 - 3z = 9
- 18 - 18
-3z = -9
-3 -3
z = 3
5x - 2y + z = 8
5(-1) - 2y + 3 = 8
-5 - 2y + 3 = 8
-2y - 5 + 3 = 8
-2y - 2 = 8
+ 2 + 2
-2y = 10
-2 -2
y = -5
(x, y, z) = (-1, -5, 3)
we know that
If a ordered pair (x,y) is a solution of the equation, then the ordered pair must satisfy the equation
we have the equation

Let's verify all the cases to determine the solution to the problem.
<u>case A)</u> point 
Substitute the values of x and y in the equation



-------> is true
therefore
The point
is a solution of the equation
<u>case B)</u> point 
Substitute the values of x and y in the equation



-------> is true
therefore
The point
is a solution of the equation
<u>case C)</u> point 
Substitute the values of x and y in the equation



-------> is not true
therefore
The point
is not a solution of the equation
<u>case D)</u> point 
Substitute the values of x and y in the equation



-------> is not true
therefore
The point
is not a solution of the equation
therefore
<u>the answer is </u>


For this problem you have yo set up two equations.
White shirts = w Yellow shirts = y
1st: w + y = 21
2nd: 9.95w + 11.50y = 235.30
Now we're going to do system of equations using substitution.
If w + y = 21, then y = 21 - w
If y = 21 - w, then you can substitute this in the second equation for y.
9.95w + 11.50(21 - w) = 235.30
9.95w + 241.5 - 11.50w = 235.30
-1.55w + 241.5 = 235.30
-1.55w = -6.2
w = 4, so 4 whites shirt were sold.
Now I'm finding out how many yellow shirts were sold using one of the two equations at the top.
w + y = 21
4 + y = 21
y = 17
So 17 yellow shirts were sold and 4 white shirts were sold.
Answer:
I think the answer is 60
Step-by-step explanation:
I am sorry if it s wrong