Question

How do you evaluate the expression 4ab, for a=2 and b=5?

Answer 1

The result is `40`

Explanation:

`4ab` is a simple form for saying "multiply 4 times the value of `a` times the value of `b`", where `a` and `b` are two variables, which means that they can take any value you like. In fact, evaluating an expression means to plug exact values, replacing the generic name of the variable. So, in your case, replacing `a` with `2` and `b` with `5`, you have a simple multiplication among numbers: `4*2*5`, which means `8*5` (or `4*10`, if you like), which is `40`.