Write an expression for the calculation add 34 and 6 and then multiply 3

We need to write an expression for "add 34 and 6 and then multiply 3"

"Add" represents + operation.

"multiply" represents * operation.

We need to add 34 and 6.

So, we can write 34+6 and then we need multiply the sum by 3.

So, we need to keep above addition of 34 and 6 in parantehsis. We get

(34+6) * 3.

So, the final expression is (34+6) * 3.