Replace the values of a and b in the formula
2a - b:
(2 * 1.235) - (-16.04) = 2.47 + 16.04 = 18.51
£110 as 45mins times 4 radiators divided by 60 mins =3 hours
3 hours + 1 hour = 4 hours
4 hours times £20= £80
£80+£30=£110
58 degrees bra cause the arc is 58 degrees and due to congruent angles x is also 58 degrees