for the equation -x+4y, find x when y=3?

Question

please show steps thanks<33

I forgot to add that -x +4y=10

Answer 1

-x+4(3)=10

-x+12=10

subtract 12 from both sides. so its...
-x=-2

divide both sides by negative 1. so

X=2

Answer 2

-x +4y=10

Okay, we start out by putting in the information we do know. We know that y equals 3.

Thus: -x + 4(3) =10

Which really is: -x + 12=10

Then, we want to move all the numbers to one side of the equal sign, and leave the variable on the other side.

We do that by subtracting 12 from the left side. Of course, to maintain equality, we have to do this to the other side too! So...

-x + 12 - 12 = 10 -12

You see that I am subtracting 12 from both sides.

Well, if I take away 12 from the left side, I have only my -x remaining. And if I take away 12 from the other side, I wind up with -2.

So, here's where we're at: -x = -2

But we are not looking for the value of -x, but of POSITIVE x. Thus, I have to multiply -x by -1 to change it to a positive number, without changing it's absolute value (i.e., if it's a -2, I still want it to be a 2, only a positive 2).

Remember, though, if I multiply one side by -1, I have to do the same thing to the other side, or you'll lose the equality.

So, -x * -1 = -2 * -1

That means that x = 2.

Now, let's check our work....

-2 + 4(3) = 10

Let's spell it out further....

-2 + 12 = 10

Indeed, if you take 2 away from 12, you get 10. Which means that: 10 = 10 (which is, of course, true).

God bless you!

Answer 3

-x + 4y = 10

-x + 4(3) = 10
-x + 12 = 10
-x = -2
x = 2

Answer 4

-x+4y = 10
-x + 4*3 = 10
-x + 12 = 10
-x +12 -12 = 10 - 12
-x = -2
x = 2

Answer 5

first, you have your equation: -x +4y = 10. you know y = 3, so plug it in to the equation.
now you have:
-x + 4(3) = 10
-x + 12 = 10
subract 12 from both sides to get x alone
-x = -2
multiply by -1 to make it positive
x = 2
=]]

Answer 6

-x + 4y = 10
-x + 4(3) = 10
-x + 12 = 10
-x = 10 - 12
x = 2

Answer 7

-x+4y=10 when y=3 x=2

-x+12=10
-x+12-12=10-12
-x=-2
-x/-1=-2/-1
x=2