Question

substitution method
3x+5y=-3
-7x+y=45

Answer 1

help with this one pat18 please i'm struggling with these problems
substitution method
3x+5y=-3
-7x+y=45

Answer 2

In these kinds of problems you want to solve for either x or y on ONE of the equations. Let me show you why.
The second equation is easier to solve to y so let's do that first.

-7x+y=45
Add 7x to both sides.
y=45+7x

Now you can substitute y into the first equation! So we have 3x+5y=-3, right? Put the value we got for y (45+7x) so:

3x+5(45+x)=-3. Now let's solve it.

3x+225+5x=-3
3x+5x=-228
8x=-228
x=-28.5

Now remember how we solved for the y equation earlier? Now we can substitute the value for x in that equation.

y=45+7x. So y=45+7(-28.5). Now let's solve.
y=45+7(-28.5)
y=45-199.5
y=-154.5

So the solution to this equation is: (-28.5, -154.5)

Answer 3

It's the solution to the system of equations, rather.*