Question 1089041
Take the first number multiply by the second then add the product to the first number.
I'm going to use the dollar sign as the operator to minimize confusion.
1$4={{{1*4+1=4+1=5}}}
2$5={{{2*5+2=10+2=12}}}
3$6={{{3*6+3=18+3=21}}}
So then now you know the operations required, solve for 5$8.