I believe the answer would be this:
-y^2 - 21
25 cubic centimeters....
Hope this helps! all you had to do it multipley <span />
180 * 365 = 65700 litres/year
65700 / 1000 = 65.7 m^3/year
0.9122 * 65.7 = £59.932 for water used
28.20 + 59.93 = £88.13 for water meter annually
£88.13 < £107 so yes, he should have a water meter.
Opposite angles are equal. An the angles on a straight line sum to make 180. As a result:
Y=105 z=75 x=75
Just remember that the word "of" means "multiply" in mathematical terms
Now lets get started working out this problem of yours

Also, remember:

and down is rounded to

|

and up is going closer to