2x+5y= 9
4x-7y= -16 And
3x-5y=7
x-2y=3
2007-01-31 08:45:23 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
Ok for the person that answered 2nd, you said to multiply -3 to the second equation, which was x-2y=3. When I do that I get the equation as -3x+6= -9? Am I wrong? I get my final anwer as ( -1,-2).
2007-01-31 15:20:32 · update #1
2x+5y= 9 <-- Eq 1
4x-7y= -16 <-- Eq 2
Multiply Eq 1 by -2 getting:
-4x -10y = -18 <-- Eq 3
Add Eq 3 to Eq 2 getting:
-17y = -34
y = 2
substitute 2 for y in Eq1 getting:
4x-7(2)=-16
4x-14 = -16
4x = -2
x = -1/2
3x-5y=7 <-- Eq1
x-2y=3 <-- Eq 2
Multiply Eq 2 by -3 getting:
-3x+6y =-6 <-- Eq 3
Add Eq 3 to Eq 1 getting:
y = 1
Substiute 1 for y in Eq 1 getting:
3x -5(1) = 7
3x-5 = 7
3x = 12
x = 4
2007-01-31 08:59:21 · answer #1 · answered by ironduke8159 7 · 0⤊ 0⤋
4
2007-02-02 04:52:55 · answer #2 · answered by greg b 1 · 0⤊ 0⤋
So somewhat it is actual written out for you: x - y = a million x + y = 7 so which you upload them and the unfavorable y cancels with the useful y ( -y+y = 0) and the x and x make 2x (x+x=2x) so which you have: 2x = 8 x=4 by using fact that all of us be attentive to x=4, we can plug it in and actual discover that y=3. x=4 y=3.
2016-12-16 17:54:51 · answer #3 · answered by ? 4 · 0⤊ 0⤋
well for the first set you would bring down the y term and divide by 5 and you can do the rest by doing the exact same thing. Now if you are wondering about systems then you would have to create opposites to make them work. If you need extra help, don't hesitate to call back.
2007-01-31 08:57:51 · answer #4 · answered by Vic 3 · 0⤊ 0⤋