Solve the system of equations using the addition (elimination) method.
If the answer is a unique solution, present it as an ordered pair: (x, y). If not, specify whether the answer is “no solution” or “infinitely many solutions.”
2x – 7y = 3
-4x + 14y = -9
2007-09-18 07:43:07 · 6 answers · asked by spanishfly_100 1 in Science & Mathematics ➔ Mathematics
multiply 1st equation by 2:
4x - 14y = 6
-4x + 14y = -9
--------------------
0 = -3
no solution <== both lines have same slope and never cross
2007-09-18 07:49:44 · answer #1 · answered by Becky M 4 · 0⤊ 1⤋
equation 1 2x-7y=3
equation 2 -4x+14y=-9
step 1-multiply equation 1 times 2 (so you can cancel one of the terms, either x or y)
2(2x-7y)=3(2)
4x-14y=6 < < < new equation 1
equation 1 4x-14y=6
equation 2 -4x+14y=-9
step 2- combine the two equations together
(4x, -4x) (-14y,14y) both cancel out
your left with:
0=-3 no solutions
2007-09-18 07:58:10 · answer #2 · answered by jessi 2 · 0⤊ 0⤋
x + 5y = 4 2x – 5y = 2 Add these 2 equations together 3x + 0 = 6 x = 2 Substitute x into 1st equation 2 + 5y = 4 y = 2/5 Check answer using 2nd equation 2(2) – 5(2/5) = 2 4 – 2 = 2 2 = 2 (x, y) = (2, 2/5) QED
2016-05-17 21:51:07 · answer #3 · answered by Anonymous · 0⤊ 0⤋
2x – 7y = 3
-4x + 14y = -9
Add the two equations
(2x-7y) + (-4x + 14y) = 3 - 9
Group like terms
2x-4x +14y - 7y = -6
Simplify
-2x + 7y = -6
Add 2x - 7y = 3
(-2x + 7y) + (2x - 7y) = -6 + 3
Group like terms
-2x + 2x + 7y - 7y = -3
0 = -3
NO SOLUTION
2007-09-18 07:55:00 · answer #4 · answered by PeterT 5 · 0⤊ 0⤋
2x – 7y = 3
-4x + 14y = -9
2x - 7y = 3
4x -14y = 9
I believe these lines are parallell and don't have a solution.
2007-09-18 08:00:15 · answer #5 · answered by Will 4 · 0⤊ 0⤋
no solutions
double 1st equation and add thru
0=-3
2007-09-18 07:49:52 · answer #6 · answered by Kenneth H 3 · 0⤊ 1⤋