Easy, but somewhat complicated.
Here's how:
50 * 10 = 500
20 * 20 = 200
10 * 30 = 300
Add up the numbers
500+300+200= 1,000
After this I got confused on what to do next, i hope either you can figure it out next or someone finishes explaining.
Sorry for not being able 2 finish D:
B. Addition
Explanation: there’s no exponents or multiplication in the expression