My answer is 45. But there might be 2 schools of thought here.
- Adding the sum of the previous equation results in the next value to be added to the next equation. 1+4=5 +2+5=12 and so on resulting in an answer of 34 for the last equation.
- Assuming there is a pattern involved one must add the next logical equation 4+7+ the value of the previous equation 21 nets 32, then continue with the next equation to result in 45.