2006-10-08 14:11:36 · 8 answers · asked by xinnybuxlrie 5 in Science & Mathematics ➔ Mathematics
4x + 2y = 100
x + y = 36
Now multiplying eqn 2 by 2
4x + 2y = 100
2x + 2y = 72
subtracting 2nd from 1st
2x = 28
x = 14
substituting x = 14 in eqn 2
x + y = 36
y = 36 - 14
y = 22
2006-10-08 14:14:01 · answer #1 · answered by aazib_1 3 · 1⤊ 1⤋
4x + 2y=100
x + y =36
you multiply the second equation by -2 and that equals-
-2x + -2y=-72
then add the 2 equations together witch equals
2x=28
x=14
then u choose an equation to plug in the x=14
14+y=36
u subtract 14 from each side which becomes
y=22
then to be sure u plug the numbers into the questions
4(14)+2(22)=100
56+44=100
14+22=36
the answer is (14,22)
2006-10-08 21:27:14 · answer #2 · answered by academiafreak 4 · 0⤊ 0⤋
Why don't you just graph them both and find the point of intersection? Your graphing calculator will do this very nicely for you.
In the alternative, multiply the second equation by -2 and add to the first.
the result is
2x = 28
x = 14
Then substitute into the second equation
14 + y = 36
y = 22
The solution is (14 , 22)
Check:
4 (14) + 2 (22) =? 100
56 + 44 =? 100
100 = 100
2006-10-08 21:37:07 · answer #3 · answered by Anonymous · 0⤊ 0⤋
4x + 2y = 100
-2x - 2y = -72
(add them) => 2x = 28 => x = 14 and y=22
2006-10-08 21:13:59 · answer #4 · answered by Seyed Salim T 2 · 1⤊ 0⤋
4x+2y=100
2x+y=50
y= -2x + 50
x+y=36
y=-x + 36
-2x + 50 = -x + 36
x = 14
y = 22
2006-10-08 21:14:21 · answer #5 · answered by fcas80 7 · 1⤊ 1⤋
y = 36 -x
4x + 2(36 - x) = 100
4x + 72 -2x = 100
2x = 28
x = 14
y = 22
2006-10-08 21:14:17 · answer #6 · answered by Green G 2 · 1⤊ 1⤋
Make and X and Y "T chart". Plug in a few numbers for X (Like -2, -1, -0, 1, and 2), then solve for y.
2006-10-08 21:14:56 · answer #7 · answered by Anonymous · 1⤊ 1⤋
uh... what will i solve? x and y?
4x+2y=100
x+y=36
x=36-y
4(36-y)+2y=100
144-4y+2y=100
-2y=100-144
-2y=-44
y=22
x+22=36
x=36-22
x=14
SS:{x=14, y=22}
2006-10-08 21:18:53 · answer #8 · answered by harry_potter 2 · 0⤊ 1⤋