First find the sum of 513 and 7−12 and the product of 7−31 and −21.
Note that LCM of 5 and 7 is 35.
Finding the sum,
513+7−12=3513×7+(−12)×5=3591−60=3531
Finding the product,
7−31×−21=7×(−2)(−31)×1=−14−31=1431
Dividing the sum by the product,
3531÷1431=3531×3114=35×3131×14=3514=52
Hence, the required quotient is 52.