work out the value of 4a + 2b when a = 4 and b = 3

To solve this question you want to do it step by step.
Firstly replace the 'a' with '4' and calculate the first part of the sum. 4 multiplied by 4, which is 16.
Next replace 'b' with '3' and calculate the second part. 2 multiplied by 3, which is 6.
once you have calculated both values simply add them together. 16 + 6 = 22