Question

Could someone please help me with this? I need all the steps too, having a hard time understading...
4x+5y=13
3x+y=-4

and

1/3x+1/2y=5
x-2/3y=1

For the 1st one, to I multiply 2nd row by -5 to eliminate y? And in the 2nd, to I muliply everything by 3 in 2nd row to get rid of denominator?

Answer 1

4x+5y=13
3x+y=-4

To solve these using elimination multiply every term in the bottom equation by 5.

4x+5y=13
15x+5y=-20

We can now eliminate y by subtracting the first equation by the second. (although it doesn't matter which way you do it.

4x+5y=13
-9x = 33
x = 33/-9
x = -3 and 2/3

We can substitute this back into the original equation to solve for x.

4x+5y=13

4(-3 and 2/3) + 5y = 13
-44/3 + 5y = 13
5y = 88/3
y = 88/3/5
y = 83/15
y = 5.5333

x = -3 and 2/3
y = 5.5333 or 83/15
I'm 90% sure this is right, sorry if it isn't (: