We were given a function with the following expression:
[tex]B(a,b)\text{ = 3a + 7b}[/tex]And we need to calculate the value of this function for a pair of inputs. In this case a = 4 and b = 5. So we have:
[tex]\begin{gathered} B(4,5)\text{ = 3}\cdot4\text{ + 7}\cdot5 \\ B(4,5)\text{ = 12 + 35} \\ B(4,5)\text{ = 47} \end{gathered}[/tex]