Math Problem?

Question

x-2y OVER 8 = 1/2
and
3x+2y=4

My teacher didn't even go over this, so can someone explain it to me?

Answer 1

You have two unknowns, and it looks like you required to identify the unknowns. You have been given two equations. Now use the equations to calculate the unknowns.

(x - 2y) / 8 = ½
3x + 2y = 4
-----------------------
x - 2y = (½)(8)
3x + 2y = 4
-----------------------
x - 2y = 4 (multiply by -3)
3x + 2y = 4
-----------------------
-3x + 6y = -12
3x + 2y = 4 ( add them together).
-----------------------
8y = - 8
y = -8/ 8
y = -1 (Now use this value and put it back into one of the equations you started off with and calculate the x value).

3x + 2y = 4
3x + 2(-1) = 4
3x + -2 = 4
3x = 4 + 2
3x = 6
x = 6/ 3
x = 2
--------------------

Answer 2

Multiply the top one by 8 so you get:
x - 2y = 4
So
x = 4 + 2y

Plug that into the second equation
3x + 2y = 4
3 (4 + 2y) + 2y = 4
12 + 6y + 2y = 4
8y = -8
y = -1

So
x = 4 + 2 * -1 = 2

Answer 3

when you have 2 equations and I will assume that
x and y equal the same in both

you have to isolate one of the variables - THEN
substitute it in the other equation

x-2y/8 = 1/2 - - - and yeah I know x-2y is the whole numereator
so mutliply both sides by 8 (it's an equation - do the same to both sides)

come out with
x-2y = 4 and then add 2y to both sides
x = 4 +2y and now we can substutitue IF I KAN SPEL~!!!

3x + 2y = 4
3(4 + 2y) + 2y = 4
12 + 6y + 2y = 4
12 + 8y = 4 now subtract 12 from both sides
8y = -8

divide both sides by 8 and we're done!

wellllllll not quite - go back to the first equation
replace y and then solve for x - but you are on your way

Answer 4

(x - 2y)/8 = 1/2.......1, and 3x + 2y = 4.........2

Multiply 1 by 8:

x - 2y = 4, so

x = 2y + 4.

Now substitute this value of x into equation 2, to give one equation with one unknown:

3x + 2y = 4, so

3(2y + 4) + 2y = 4, so

6y + 12 + 2y = 4, so

8y = -8, so

y = -1, and

x = 2y + 4, so

x = -2 + 4, so

x = 2.

Hope this helps, Twiggy.

Answer 5

x - 2y over 8 = .5
3x +2y = 4

x-2y = 4
x = 2y +4
3( 2y +4) +2y = 4
6y + 12 + 2y =4
8y = - 8
y = -1
3x + -2 = 4
x = 2

Answer 6

it is a linear pair
the way to do this would be linear combination
multiply the top part by -3
you get -3x+3y/4= -3/2
add that with the bottom part
the x's cancel out
you get 11/4y= -5/2
which would be 2y=1
so y would equal 1/2
then substitute that in the bottom problem you started with
you get 3x+1 =4
x would equal 1
(1,1/2)

Answer 7

x = 2 and y = -1

Solve the first equation for x in terms of y. Then substitute the value for x in terms of y into the second equation and solve for a numerical value of y. Then put that value of y back into one of the original equations and solve for x.

Answer 8

Are you solving for x or for y or for both?