## Problem #1

3y means nothing to the compiler. If you want 3 times *y*, you have to say

3 * y

## Problem #2

A dash is not a minus sign.

Please note, that in the formula "total = 3y + x * (y – a) * (x + b);" you have a dash between y and a, not a minus sign

// – is a dash
// - is a minus sign
// correct formula:
total = 3 * y + x * (y - a) * (x + b);

## Problem #3

The variables *a* and *b* are not read. You read *x* and *y* instead, but you instantly overwrite their value with calculation used by the uninitialized *a* and *b*.

Did you mean:

scanf("%f", &a);
scanf("%f", &b);

instead?