Can I get help with this .You guys are the greatest You have taught me a lot?

In elimination method, you want to add the two equations together in such a way that one of the variables cancels out. Sometimes you have to multiply one equation by an integer in order to make it work. For example, if you had 7x + 3y=5 and 4x + 6y = 14, we would multiply the first equation through by -2, making it -14x - 6y = -10. That way when we added the equations we would have -6y + 6y, and the y's would cancel, allowing us to solve for x.

In your example problem, the "y"s are already going to cancel because we have +8y and -8y. So just add the equations together:

7x + 8y =29
2x - 8y = -74

(7x+8y) + (2x-8y) = 29 + (-74)
9x= -45
x= -5

Now that you know what x is, just plug it in to either equation to solve for y:

7(-5) + 8y = 29
-35 + 8y = 29
8y = 64
y= 8

So your answer is: x= -5, y= 8

X=-5 and Y=8

I think you are currently in Pre-algebra or Algebra, right?

7x + 8y = 29
2x - 8y = -74

7x + 8y = 29
8y + 7x = 29

2x - 8y = -74
8y - 2x = 74

...8y + 7x = 29
-- 8y - 2x = 74
----------------------
9x = -45

9x = -45
x = -45/9
x = -5

7x + 8y = 29
7(-5) + 8y = 29
-35 + 8y = 29
8y = 29 + 35
8y = 64
y = 64/8
y = 8

∴ x = -5 , y = 8

just add the two equations, term by term:
7x + 2x +8y +(-8y) = 29 + (-74)
collect
9x + 0 = -45 = 9x
solve x = -45/9 = -5
then plug into one of the eqn's to solve for y
I'd choose the 2nd since 2x is easy to figure
-10 - 8y = -74 so -8y = -64 so y= -64/-8 = 8
(-5,8)
=====
next a harder one
3x + 2y = 14
2x + 7y = 9
to solve by elimination you first have to examine and determine which variable x or y will be easiest to get rid of.
...x has factors of 2 & 3 while y has factors 2 & 7..so I choose x to get rid of. I multiply the top equation by a factor and the bottom by a different factor so that the factors (coefficients) in front of the x's are the same but of opposite sign
-2(3x + 2y) = -2*14
3*(2x+7y) = 3*9
===
-6x - 4y = - 28
6x +21y = 27
add 'em
-4y +21y = -28 + 27
17y = -1 or y = - 1/17
and you can plug this y into one of the eqns to solve for x.
PS there's nothing wrong with subtracting the two eqns instead of adding them. I believe this also qualifies as the elimination method, but check with teach to make sure this is ok. don't want to upset him/her.

7x+8y=29
2x-8y=-74
first you add every thing because you want to cancel the 8's (since they're + and - they just cross out)
you end up with 9x=-45
second step is divide by 9 because you want "x" to be alone
which gives you x=-5
you have found "x" but now you have to find "y"
first step is take the "x" answer which is -5 and plug it into one of the original equations
for example:
(i would choose the first one because it has no negatives)
you have 7x+8y=29 take -5 and plug it into "x" so now you have 7(-5)+8y=29
which ends up to be -30+8y=29
add 30 to both sides and you get 8y=59
last step is to divide both sides by it
and after you done that you have solved the problem

Simultaneous equations
to find x and y
add the equations together
7x + 8y =29
+
2x - 8y =-74
=
9x=-45
divide both sides by 9
x=-5
now substitute x =-5 into the first equation
7x-5+8y=29
=-35+8y=29
add 35 to each side
8y=64
divide by 8
y= 8
now to check your answer it should work when substituting both x and y into the second equation
2x-5-8x8=-74
-10-64=-74
CORRECT

hope this helped

Using the elimination method just add the two equations together and go from there. After doing that you should have a new equation that looks like this.
9x=-45. Then solve for x which in this case is -5. Now that we know that x=-5 just choose either original equation to plug in our x value to solve for y. I'll choose the first one.
7(-5)+8y=29
-35+8y=29
8y=64
y=8. So your final answer is (-5,8).

7x + 8y = 29 eq. 1
2x - 8y = -74 eq. 2

Let us eliminate y: Add the two equations:
9x + 0 = -45
x = -45/9
x = -5

From eq. 2: 2(-5) - 8y = - 74
-10 - 8y = - 74
- 8y = - 74 + 10
y = - 64/-8
y = 8

ANSWERS: x = -5, and y = 8

Hope this helps you.

teddy boy

What happened to you? See, y terms are opposite. Aren't they? so add the equations, that's all. U get 9x = -45 or x = -5. Use this value in any equation and get y = 8. ( -5, 8) is the "ordered pair".

+8y -8y gives you zero so 9x = -45, (by adding the y's and the totals) -45 divided by 9 = -5 so x=-5 plug into either equation to get y