: Rewrite the equation -8x - 5y = -45
I know first I am to solve for y
5y + 5y cancels out the 5 and leaves y
-45 minus 5 = -50
So now my equation looks like this:
-8x = -50
Now I must solve for x
-8x divided in to -50 =
16
So would my answer be:
f(16) = -8 - 5
I am really stuck on these type of problems. Thank you for
the wonderful help you give!!
No, I'm afraid this is all wrong. Let's go thru it step by step:
-8x - 5y = -45
Get rid of any term on the left which does not contain a y. So we
have to get rid of the first term, -8x. To do this we add the
opposite of -8x, namely +8x, to both sides
-8x - 5y = -45
+8x + 8x
-------------------
-5y = -45 + 8x
Now we divide every term by the coefficient of y, which is -5:
-5y -45 8x
————— = ———— + ————
-5 -5 -5
In the first term on the left, the -5's cancel and leave just y
-45 8x
y = ———— + ————
-5 -5
The first fraction on the right is just +9 since
-45 divided by -5 = +9
8x
y = 9 + ————
-5
The second fraction with the negative sign on the bottom can be
written with a minus sign in front
8x
y = 9 - ————
5
You can leave it just like this, but the usual way is to write
the second term as a fraction times x or
8
y = 9 - — x
5
Also what is common is to write the term in x first. So you
might write that as
8
y = - — x + 9
5
or
y = -(8/5)x + 9
Edwin
AnlytcPhil@aol.com
