Math homework please help.

solve the following system of equations by the addition or subtraction method.
7x+y=13
y=2x-0.5

solve the following systems of equations using the substitution method:
x+5y=4
x=5y-16

thank you for helping and please show the steps. :)

For the first equation using the addition method

7x + y = 13

y = 2x -.5

You can do what the above poster said or you can do it the long way, you need to get the similar variables on the same side of the equation.

7x + y = 13

-2x + y = -.5

Multiply the second equation by a negative to get rid of the y's.

-(-2x + y = 13) = 2x - y = .5

So it should look like this;

7x + y = 13

2x - y = .5

Now start adding!

9x = 13.5

Divide both sides by 9

x = 1.5

Now plug it in and solve for y.

7(1.5) + y = 13

10.5 + y = 13

Get y all by itself

y = 2.5

Test and see

7(1.5) + 2.5 = 13

-2(1.5) + 2.5 = -.5

Both equations work! x and y are as follows;

(x,y) = (1.5,2.5)

For equation 2 using the substitution method

x + 5y = 4

x = 5y - 16

You already have x so substitute it into the first equation and solve for y

5y - 16 + 5y = 4

10y - 16 = 4

Get the like variables together again

10y = 20

Divide by 10 to get y alone

y = 2

Now time to substitute y and solve for x

x + 5(2) = 4

x + 10 = 4

Get x all by itself

x = -6

Test and see!

-6 + 5(2) = 4

-6 = 5(2) - 16

Both equations work! x and y are as follows;

(x,y) = (-6,2)

I did this one for you only because I'm sure it's not the only one on your homework and hopefully seeing it worked out is what you need to be able to solve it on your own in the future.

So this is Algebra 1?

I won't do the problem for you, but I'll help you out :)