Just when I thought I was getting somewhere I still just can't quite crack it
I have;
3x + 2y = 3
5x - 1y = - 8
I am asked to solve the equations so this is what I have tried
(3+5)x + (2-1)y = 3 - 8
8x / 8 = - 5 / 8 = x - 0.625
3(-0.625) + 2y = 3
- 1.875 + 2y = 3
2y = 3 = 1.875
2y = 4.88
2y = 4.88
2 2
y = 2.44
Check;
3(-0.625) + 2(2.44) = 3.00
5(-0.625) - 1(2.44) = - 5.57
The latter should be -8?
Anybody see what I am getting wrong?
Thanks
David
OK here goes?
3x + 2y = 3
5x - 1y = - 8
10x + 2y = - 16
3x + 2(10x - 2y) = - 16
3x + 20x - 4y = - 16
the rest of this method I don't think works?
10x - 2y = - 16
3x + 2y = - 16
2y = - 16 + 3
2y = - 13
y = - 6.5
3x + 2 (- 6.5) = 3
3x - 13 = 3
3x = 16
x = 5.33
3(5.33) + 2(-6.5) = 15.99 - 13 = 2.99 almost there?
5(5.33) - 1(-6.5) = 26.65 - 6.5 = 20.15?????? definately not - 8????
It is difficult not to make something hard when one does not know what one is doing?
I'll try again with all the help so far, which I must say thank you to all.
3x + 2y = 3
5x - 1y = - 8
10x - 2y = - 16
3x +2y = 3
13x = - 13
x = - 1
3x + 2y = 3
3(-1) + 2y = 3
-3 + 2y = 3
2y = 3 + 3
y = 3
3x + 2y = 3
3(-1) + 2(3) = -3 + 6 = 3
5x - 1y = - 8
5(-1) - 1(3) = - 5 - 3 = - 8
so x = -1 and y = 3
Thanks all, I am still learning.