4+5+1−3= 4+5+1-3= 4+5+1−3=
According to the order of operations, we solve the exercise from left to right:
4+5=9 4+5=9 4+5=9
9+1=10 9+1=10 9+1=10
10−3=7 10-3=7 10−3=7
7