Work out the value of 2a^2 + b^3 when a = 5 and b = –3
It is best to approach this question in parts, then combine the parts to find your solution. This question may be split into parts, as follows: Firstly, if a = 5, then a2 = 52 = 5 x 5 = 25. So a2 = 25 Secondly, if b = -3, then b3 = (-3)3 = (-3) x (-3) x (-3) = 9 x (-3) = -27. So b3 = -27 Finally we can combine the above parts: 2a2 + b3 = 2(25) + (-27) = 2 x 25 - 27 = 50 - 27 = 23 So the value of 2a2 + b3 is 23.
