Question 685
Let's make the number of girls g and the number of boys b.

{{{g+b=466}}}

There are 212 more girls than boys so:

{{{g=b+212}}}

If we substitute this value for g into the first equation we get:

{{{(b+212)+b=466}}}

Get rid of the brackets:

{{{b+212+b=466}}}

Add like terms:

{{{2b+212=466}}}

Subtract 212 from each side:

{{{2b=254}}}

Divide by 2:

{{{b=127}}}

So the number of boys in the class is 127.