Solving systems using Substitution

[Young&&inlove]

Here are the equations:

x+3y=9
y=-3/2+13/2

I simply don't get how to do it.
Will someone please help me.

If someone could get me headed in the right direction Ithink I'll be able to get it.

 

[skeeter]

does the second equation have the variable "x" in it? if so, where? if not, say "correct as written".

 

[Goistein]

For the first equation, put x in terms of y.
x=9-3y

Next substitute that in place of x in the second equation getting y=-1.5(9-3y)+6.5, and solve for y. Then solve for x using x=9-3y.

 

[Young&&inlove]

Oops.

The second equation is y=-3/2x+13/2.
Sorry about that.

-Marissa

 

[Denis]

Re: Oops.

The second equation is y=-3/2x+13/2.
Sorry about that.

Well then, you have:
x + 3y = 9 ; x = 9 - 3y [1]

y = -3x/2 + 13/2
2y = -3x + 13
3x + 2y = 13 [2]

Substitute [1] in [2] : let's see you finish it :shock: