2x+3y=28
4x-5y=-10
2007-11-04 13:53:54 · 3 answers · asked by Jamie M 1 in Science & Mathematics ➔ Mathematics
10x + 15y = 140
12x - 15y = - 30-----ADD
22x = 110
x = 5
10 + 3y = 28
3y = 18
y = 6
x = 5 , y = 6
2007-11-04 21:58:26 · answer #1 · answered by Como 7 · 0⤊ 1⤋
First, multiply the top equation so that you are able to clear out x's.
-2(2x+3y=28)
4x-5y=-10
-4x-6y=-56
+(4x-5y=-10)
after adding, you get that -11y=-66, so y=6. Plug this back into either equation.
2x+3(6)=28
2x+18=28
2x=10
x=5
2007-11-04 22:01:54 · answer #2 · answered by Mother Pucker 3 · 1⤊ 0⤋
A) 2x+3y=28
B) 4x-5y=-10
multiply equation A by (-2)
A) -4x -6y = -56
B) 4x -5y = -10
Add A + B
-4x + 4x -6y - 5y = -56 - 10
or
-6y - 5y = -56 - 10
or
-11y = -66
or y = 6
put y=6 into equation A
A) 2x+3y=28
2x + 3*6 = 28
or
2x = 28 - 18
or
2x = 10
or
x = 5
2007-11-04 22:02:21 · answer #3 · answered by Ms. M 3 · 0⤊ 0⤋