Alright. So the problem is
10*12+-15/5+2(9-4)
Lets break down what we can for now
First focus on parenthesized, multiplying, and dividing in the problem.
10*12=120 15/5=3 (9-4)=5
120+-3+2*5
So the next step, we see 2*5 and a negative -3 on top of a positive symbol.
2*5=10
120-3+10
Now subtract from the left to the right and get your answer.
120-3=117
117+10=127