There are 812 students in a school. There are 36 more girls than boys. How many girls are there?

There are 812 students in a school. There are 36 more girls than boys. How many girls are there?

Let b be boys
Let g be girls

We're given two equations:

1. b + g = 812
2. g = b + 36

Rearrange equation 2 to subtract b from each side:

1. 
   
   
   • b + g = 812
   • -b + g = 36

Add equation (1) to equation (2):
b - b + 2g = 812 + 36

The b's cancel:
2g = 848

Divide each side by 2:
2g/2 = 848/2
g = 424

To find b, we put g= 424 into equation 1:
b + 424 = 812
b = 812 - 424
b = 388