Homework Help: math, really need some feedback on this asap.

Posted by SAP on Thursday, September 30, 2010 at 11:00pm.

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?

math, really need some feedback on this asap. - SAP, Friday, October 1, 2010 at 7:38pm
After re-working the problem, I'm pretty confident this is the correct answer to the 2nd part of the problem. Can someone confirm my work....

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

Answer this Question

Related Questions

math need asap - 7r-4s=-7 (7) 4r+7s=61 (4) 49r - 28s = -49 16r + 28s = 244...
Math need by 9pm cst - Solve by elimination method. Please show step by step ...
Algebra - I am stumped by these two LCM questions for some reason. Find The LCM ...
math - 16min 28s/4
algebra - Solve by elimination 7r-5s=41 5r+7s=61
mat/116 - solve by elimination method. 7r-2s=61 2r+7s=25
Maath - 5(4r-3c)-2(7r-9c)=0 solve for r This is all I know how to do and don'...
8th grade Math - I'm actually in 7th grade, but I'm doing 8th grade pre-...
ALGEBRA - add (r-7s+2)+(4r+6s)+(s+5) do i add like terms: (4r^2)+(-2s)+(7)
m - Ok here are a few more 1. collect like terms 12r+6s-3r-9s A:9r-3s 2. ...

For Further Reading

First Name:
School Subject:
Answer: