I can't figure this bloody equation out!!! >=(
7x-5y=40
3x-2y=16
It looks easy but i can't figure it out...Show your work, please..
2007-11-28 06:50:11 · 3 answers · asked by Water Temple boss : Morpha 1 in Science & Mathematics ➔ Mathematics
Hmm, i forgot i can multiply both equations and not just one...Thanks people (;
2007-11-28 07:01:30 · update #1
Whoops, it's actually 5 in the second equation instead of 16 so it would be : 7x-5y=40
3x-2y=5
14x-10y=80
15x-10y=25
-----------------
-1x = 55
x=-55
(2nd eqt substitution)
-165-2y=5
-2y=170
y=-85
(Check)
-165-(-425)=40
=D Thanks for help people
2007-11-28 07:14:44 · update #2
7x-5y=40
3x-2y=16
21x - 15y = 120
21x - 14y = 112
-y = 8
y = -8
3x - 2(-8) = 16
3x + 16 = 16
3x = 0
x = 0
x=0, y= -8
2007-11-28 06:58:26 · answer #1 · answered by norman 7 · 0⤊ 0⤋
Multiply the first by 2 and get 14x -10y =80
and the second by -5 so you can add them together and eliminate the ys...........-15x + 10y = -80
-x =0
x=0
now solve for y: y=-8
2007-11-28 06:58:35 · answer #2 · answered by mom 7 · 0⤊ 0⤋
7x - 5y = 40 ------------------------eqn(1)
3x - 2y = 16 -------------------------eqn(2)
multiply eqn(1) with 2
14x - 10y = 80 ----------------------eqn(3)
multiply eqn(2) with 5
15x - 10y = 80 ----------------------eqn(4)
subtract eqn(3) from eqn(4)
x = 0
substitute x = 0 in eqn(2)
0 - 2y = 16
2y = -16
y = -16/2 = -8
so x = 0 and y = -8
2007-11-28 06:59:50 · answer #3 · answered by mohanrao d 7 · 0⤊ 0⤋