Where do you insert parenthesis to make this equation true: 3x5+4-2x2+6-4=15

Answer 1

3x5+4-2x2+6-4=15

since the only two odd numbers are the 3x5, and only the product of two odds or the sum of an even and an odd is odd, we must have either

3x(5...) or (3x5)+...

see what you can do with that