Share
Explore BrainMass

Solving Systems of Equations

1. y-2x=0
y=8x-9

What is the solution of the system of equations?
(i need graph also)

2. r-6s=0
9r-8s=230
What is the solution of the system?

3. x+y= -13
9x+y= -61
What is the solution of the system?

4. (1,2); 6x-5y= -4
2x-7y= -12
is the given ordered pair a solution of the system?
yes or no

5. 5x+8y= 27
8x-8y= -144
what is the solution of the system?

6. 9x+6y= 15
-7+y= 28
what is the solution of the system?

7. x+y= 9
y=x+1
what is the solution of the system?

8. 1/2 x + 2/3 y = 2/3
2/3 x - 3/5 y = 1/5
what is the solution of the system?

9. (5,4) 7x-4y= 19
8x-5y= 20
is the given ordered pair a solution of the system?
yes or no

10. x+y= 11
9x-y= 69
what is the solution of the system?

11. p=38+q
9p= -4q+381
what is the solution of the system?

12. 3x-y= 3
4x+y= 4
what is the solution of the system of equations?
(need graph also)

13. 3r-7s= -48
7r+3s= 62
what is the solution of the system?

14. x+y= -2
x-y= 6
what is the solution of the system?

15. x-y= -12
2x-9y= -66
what is the solution of the system?

16. x-y= 15
x+y= 3
what is the solution of the system?

Solution Preview

1. y-2x=0
y=8x-9
Then (8x-9) - 2x = 0, then 8x - 9 - 2x = 0, then 6x - 9 = 0, then x = 3/2
So y = 8x - 9 = 3
The solution is x = 3/2 and y = 3, or (3/2, 3)
The graph is attached.

2. r-6s=0 (1)
9r-8s=230 (2)
From (1), we get r = 6s, then we put in (2) and have
9(6s) - 8s = 230, then 54s - 8s = 230, then 46s = 230, then s = 5
so r = 6s = 30
The solution is r = 30, s = 5.

3. x+y= -13 (1)
9x+y= -61 (2)
(2)-(1), then get 8x = -61+13 = -48, then x = -6. Since x + y = -13, then y = -x - 13 = -7.
The solution is x = -6, y = -7, or (-6, -7)

4. (1,2); 6x-5y= -4
2x-7y= -12
is the given ordered pair a solution of the system?
YES

5. 5x+8y= 27 (1)
8x-8y= -144 (2)
(1)+(2) and get 13x = -144 + 27 ...

Solution Summary

Systems of equations are solved.

$2.19