Answer:
(x,y,z) -> (2,4,1)
Step-by-step explanation:
-7x + y + z = -9
-7x + 5y - 9z = -3
7x - 6y + 4z = -6
Pick two pairs:
-7x + 5y - 9z = -3
7x - 6y + 4z = -6
and
-7x + y + z = -9
-7x + 5y - 9z = -3
Eliminate the same variable from each system:
-7x + 5y - 9z = -3
7x - 6y + 4z = -6
+ 5y - 9z = -3
- 6y + 4z = -6
<u><em>-1y - 5z = - 9</em></u>
-7x + y + z = -9
-7x + 5y - 9z = -3
-7x + y + z = -9
7x - 5y + 9z = 3
<u><em>-4y - 10z = -6</em></u>
Solve the system of the two new equations:
-1y - 5z = - 9 -> -4 ( -1y - 5z = - 9) -> 4y + 20z = 36
-4y - 10z = -6 -> -4y - 10z = -6 -> -4y - 10z = -6
10z = 30
Thus, z = 3
-4y - 10z = -6
-4y - 10(3) = -6
-4y - 30 = -6
-4y = 24
Thus, y = -6
Substitute into one of the original equations:
-7x + y + z = -9
-7x + (-6) + (3) = -9
7x + -3 = -9
7x = -6
x =
Answer:

Step-by-step explanation:
Let x be the number of games
Cost of 1 game = $9
Cost of x games = 9x
he gets a student discount of $10.
So, Cost after discount = 9x-10
Let the total cost be T
So, 
So, An equation to represent the total cost of playing laser tag including the discount is 
Answer:
-6
Step-by-step explanation:
Answer:
Length of sides ;
3.5 yards ; 10 yards.
Step-by-step explanation:
Let :
Side 1 = x
Side 2 = y
x = 2y + 3
Perimeter (P) of rectangle = 2(side1 + side2)
Perimeter, P = 27
P = 2(x + y)
27 = 2(2y + 3 + y)
27 = 2(3y + 3)
27 = 6y + 6
27 - 6 = 6y
21 = 6y
y = 21/6
y = 3.5
From ; x = 2y + 3
x = 2(3.5) + 3
x = 7 + 3
x = 10