Question

Which computation should be done last 2x9 -3x5+4?

Answer 1

2 x 9 - 3 x 5 + 4

In math/s we have the rule called BEDMAS
(a.k.a. BODMAS, BIDMAS, PEDMAS, etc)

Brackets
Exponent
Division
Multiplication
Addition
Subtraction

We go from top to bottom of the list of rules for every math equation. There’s just one exception, addition and subtraction are treated equally, and so when we have an equation with just addition and subtraction, we work left to right

2 x 9 - 3 x 5 + 4

We have no brackets and no exponents, and there’s nothing to divide.
So, we do multiplication
18 - 15 + 4

If you remember, addition and subtraction are treated the same. Therefore, we work left to right.
18 - 15 + 4 = 7

You can type your question into goorgle or a calculator, and you’ll get 7!