Posted by **SAP** on Thursday, September 30, 2010 at 10:01pm.

7r-4s=-7 (7)

4r+7s=61 (4)

49r - 28s = -49

16r + 28s = 244

---------------

65r = 195

195/65 = 3 (simplified) (3, is the first number of the ordered pair.)

Now this is the part that I get lost on. I know I am suppose to substitute 3 into one of the equations above, but how do I determine which one. So if I substitute 3 into the 1st equation:

7(3)-4s= -7

21 - 4s= -7

------------

21 = -7 would my answer be -7/21

Substitute 3 into the 2nd equation:

4(3)+7s = 61

12 + 7s = 61

-------------

12 = 61 would my answer be 61/12

(3, is the first number of the ordered pair.)

(3,-7/21) or (3,61/12) which ordered pair is correct?

## Answer this Question

## Related Questions

- math, really need some feedback on this asap. - 7r-4s=-7 (7) 4r+7s=61 (4) 49r...
- math - 16min 28s/4
- math - 15/13 * 13/15 is it: 13*13=169 15*15=225 =225/169 or 13*15=195 15*13=195...
- math need asap - 4x+5y=27 x=26-4y 4(26-4y) + 5y = 27 104 - 16y+ 5y = 27 -21y...
- Algebra - Can someone please check my answers. 1. Solve. –7x + 1 + 8x = x + 1 A...
- science - A half-life of mercury-195 is 31 hours. If you start with a sample of ...
- calculus - Find the midpoint of the line segment joining the point P1 and P2. P1...
- Math - find the intercept and graph. -x+3y=-6 I need to complete the ordered ...
- science - A ball weighing 1.78 N is shot through a launcher,achieving a speed (...
- pre-algebra - The perimeter of a triangle is 195 mm.If the lengths of the sides ...