We start with:
y=2x-15
y=5x
Now, we have a perfectly set-up variable we can get rid of: <em>y.</em>
But we need to make either the top or bottom equation negative, so for simplicity, let's make the bottom one negative.
y=2x-15
(-y)=(-5x)
Now simplify.
-3x-15=0
Add 3x on both sides.
3x=15
Divide by 3 on both sides.
x=5
255 l ------ 340km
x l -------- 100km
100*255=340x
25500=340x
x=75 litres
3.19 - 1.99 = 1.20 increase in 4 years
1.20/4 = 0.30
rate of change is 0.30 per year (30 cents per year)
Add the length width and height all together
The first step for solving this equation is to determine the defined range.

, x ≠ 1
Remember that when the denominators of both fractions are the same,, you need to set the numerators equal. This will look like the following:

= 5
Take the root of both sides of the equation and remember to use both positive and negative roots.
x +/-
![\sqrt[4]{5}](https://tex.z-dn.net/?f=%20%5Csqrt%5B4%5D%7B5%7D)
Separate the solutions.
x =
![\sqrt[4]{5}](https://tex.z-dn.net/?f=%20%5Csqrt%5B4%5D%7B5%7D)
, x ≠ 1
x = -
Check if the solution is in the defined range.
x =
x = -
This means that the final solution to your question are the following:
x =
x = -
Let me know if you have any further questions.
:)