# math need asap

posted by .

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?

## Similar Questions

1. ### Algebra

Can someone please check my answers. 1. Solve. –7x + 1 + 8x = x + 1 A) Identity B) No solution C) 1 D) 0 My answer: A) Identity 2.The length of one of the equal legs of an isosceles triangle is 8 cm less than 4 times the length of …
2. ### math

15/13 * 13/15 is it: 13*13=169 15*15=225 =225/169 or 13*15=195 15*13=195 =195/195=1

16min 28s/4
4. ### math need asap

4x+5y=27 x=26-4y 4(26-4y) + 5y = 27 104 - 16y+ 5y = 27 -21y = - 77 21y = 77 y = 77/31 Now, I’m suppose to return to the 2nd equation x=26-4y and substitute 77/31 for x, I don’t understand if the is correct way or how to get the …
5. ### math, really need some feedback on this asap.

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 …
6. ### science

A half-life of mercury-195 is 31 hours. If you start with a sample of 5.00g of pure mercury-195, how much of it will still be present after 93 hours?
7. ### math

Multiply the following polynomials. 1. -2r(8r+5) A. -16r^2+5 B. -16r^2+10 C. -16r^2-10r D. -16r^2-10 2. 2a(a^2+4a) A. 2a^2+6a^2 B. 2a^3+8a^2 C. 2a+6a D. 2a^3+6a^2 3. (3y)(3y-2) A. 9y^2-6 B. 9y^2+5y C. 9y^2+1 D. 9y^2-6y 1.B 2.A 3.B
8. ### MS. SUE?? MATH (8TH) CONNECTIONS

I have 3 questions. Multiply the polynomials. -2r(8r+5) a. -16r^2 + 5 b. -16r^2 + 10 c. -16r^2- 10r d. -16r^2 - 10 ^2a(a^2 + 4a) a. 2a^2 + 6a^2 b. 2a^3 + 8a^2 c. 2a + 6a d. 2a^3 + 6a^2 (3y)(3y-2) a. 9y^2 - 6 b. 9y^2 + 5y c. 9y^2 + …
9. ### Math "Need Help Asap"!

6.)-2r(8r+5) A.)-16r^2+5) B.)-16r^2+10 C.)-16r^2-10r D.)-16r^2-10 HELP?