Question 259801
Let's re-write it like this,
{{{10+50=80-A}}}
{{{60=80-A}}}
What number subtracted from 80 gives you 60?
{{{A=20}}}
.
.
.
{{{90-30=20+B}}}
{{{60=20+B}}}
What number added to 20 gives you 60?
{{{B=40}}}