Answer: 
Step-by-step explanation:
Let be "x" the original volume of the solution (in milliliters) before the acid was added and "y" the volume of the solution (in milliliters) after the addition of the acid.
Set up a system of equations:

Applying the Substitution Method, you can substitute the second equation into the first equation and then solve for "x":
If I’m getting this right the equation is: 0.00045 - 2.5 x 10 - 5? The dot in between 2.5 and 10 indicates a multiplication sign
So...
0.00045 - (2.5 x 10) - 5
0.00045 - 25 - 5
= -29.9999 -> -30
Slope intercept form is y = mx + c.
<em>(where m is the slope, and c is the intercept - hence slope intercept form)</em>
So all you have to do is rearrange the inequality to have y by itself.
-6x + 3y > - 45 <em>(add 6x to both sides)</em>
3y > - 45 + 6x <em>(divide both sides by 3)</em>
y > - 15 + 2x <em>(put the 2x infront of the - 15) </em>
y > 2x - 15
- - - - - - - - - - - - - - - - - - - - - - -
Answer:
y > 2x - 15
- - - - - - - - - - - - - - - - - - - - - - -
20% * 158.08 =31.616
or
20% * £158.08 =48.1005824