7x+2y-10
-7x+y- -16
2007-05-30 09:49:27 · 6 answers · asked by kissaboo06 2 in Science & Mathematics ➔ Mathematics
x = 2
y = -2
I assumed that the equations are
7x + 2y = 10 _______ (1)
-7x + y = -16 _______(2)
Adding eqn. (1) and (2) we can eliminate 'x'
2y + y = 10 - 16
3y = -6
y = -2
Substituting this value of 'y' in (1)
7x + 2(-2) = 10
7x = 14
x = 2
2007-05-30 09:52:18 · answer #1 · answered by psbhowmick 6 · 1⤊ 0⤋
7x + 2y - 10
- 7x + y- - 16 2 negatives turn into a positive
7x + 2y - 10
-7x + y + 16 NOW SOLVE
3y + 6 Divide by 3 to get rid of the number 3
3. . . 3 the dots are there so the 3s do not move
ignore the dots.
y = 2 Your y value is 2
7x + 2y - 10
7x + 2(2) - 10 = Now you must substitute 2 in for y
7x + 4 - 10 =
-4.....-4 Now you must substact 4 on both sides
7x = 14
7. . . . 7 Now you must divide by 7
Pay no attention to the dots, they are
to align the 7s correctly
x = 2 Your x value is 2
Your final awnser is (2, 2)
2007-05-30 17:19:44 · answer #2 · answered by Robert H 1 · 0⤊ 1⤋
I don't see any equals-signs in your typing, so I'll assume you mean:
7x + 2y = 10
-7x + y = -16
Note that the coefficients of x in the two equations are additive inverses (7 vs -7). As a result of that, adding those equations vertically eliminates x and yields:
7x + 2y = 10
-7x + y = -16
==========
0 + 3y = -6
... which simplifies to:
y = -2
You can plug that value for y back in to either original equation to find x:
7x + 2y = 10
7x + 2*(-2) = 10
7x = 14
x = 2
2007-05-30 16:53:51 · answer #3 · answered by McFate 7 · 0⤊ 1⤋
No equal signs, i'm assuming you mean :
7x +2y = 10 -------------- (1)
-7x + y = -16 -------------- (2)
adding equations (1) &(2)
3y = - 6
y = - 2
substituting y = -2 in equation (1)
7x + 2(-2) = 10
7x + (- 4) = 10
7x = 14
x = 2
2007-05-30 17:02:56 · answer #4 · answered by Dude2001 2 · 0⤊ 0⤋
Add the two equations together to eliminate x
We get:
3y = -6
so y = -6/3 = -2
If y = -2
Since 7x+2y =10
then 7x + 2(-2) = 10
and 7x = 14
so x = 14/7 = 2
We have found that x=2 and y=-2
2007-05-30 16:55:33 · answer #5 · answered by peateargryfin 5 · 0⤊ 0⤋
7x+2y=10
-7x+y= -16
---------------------
3y= -6
y=-2
substitute y for -2 in one of the equations and solve for x
7x+2y-10 (*note* I assumed that this whole equation is = to 0, so i can move the 10 over onto the other side)
7x+2(-2)=0
7x-4=0
x= 4/7
2007-05-30 16:54:08 · answer #6 · answered by Sum Girl 4 · 0⤊ 1⤋