Linear simultaneous equations help please D:

Printable View

• Feb 2nd 2008, 11:51 PM
Hikaru
Solved! =D Thankyou! =D
Heya! (Rofl)

I need some help solving an equation. =]

We have to find out what x and y stand for.

For the last 10 sums, all I had to do was draw a giant sum, and cancel whatever is canceled out and work it out from there. But I can't do it for this one:

4x + 2y = 20
3x + 2y = 16

So what do I do?

(Also, the teacher said that some of the answers say "No solution". Do you think this a "No solution" answer?)
• Feb 3rd 2008, 12:20 AM
mr fantastic
Quote:

Originally Posted by Hikaru
Heya! (Rofl)

I need some help solving an equation. =]

We have to find out what x and y stand for.

For the last 10 sums, all I had to do was draw a giant sum, and cancel whatever is canceled out and work it out from there. But I can't do it for this one:

4x + 2y = 20 .... (1)

3x + 2y = 16 .... (2)

So what do I do?

(Also, the teacher said that some of the answers say "No solution". Do you think this a "No solution" answer?)

Mr F edit in red.

Subtract equation (2) from equation (1): (4x + 2y) - (3x + 2y) = 20 - 16 => x = 4.

Sub x = 4 into equation (1): 4(4) + 2y = 20 => 16 + 2y = 20 => 2y = 4 => y = 2.
• Feb 3rd 2008, 12:26 AM
Hikaru
Quote:

Originally Posted by mr fantastic
Mr F edit in red.

Subtract equation (2) from equation (1): (4x + 2y) - (3x + 2y) = 20 - 16 => x = 4.

Sub x = 4 into equation (1): 4(4) + 2y = 20 => 16 + 2y = 20 => 2y = 4 => y = 2.

Ohhhhh coolio. =] Thanks!