Hi there!
a. 8x^2 - 1
(x^2 - 4x + 5) + (7x^2 + 4x - 6)
= x^2 + 7x^2 - 4x + 4x - 1
= 8x^2 - 1
b. 5x^2 + 7x - 7
(7x^2 + 4x - 6) - (2x^2 - 3x + 1)
= 7x^2 + 4x - 6 - 2x^2 + 3x - 1
= 7x^2 - 2x^2 + 4x + 3x - 6 - 1
= 5x^2 + 7x -7
Hope this helps!
We can easily work out the meter reading in October. It comes out to be 32347 + 972. So the reading in October must be around 33319.
SO the answer to second question is really easy to figure out too. As we know that one unit costs 14 p we can simply multiply the cost with the number of units consumed.
So for 972 units if we multiply by 14 we get the cost to be around somewhere 13608 p.
The answer is 80 because 800÷10=80
