a) [(15+20) * (15+20) - 100]/2
b) 15 + 20 - [(50+7)*(50+7)]/5
c) 15 + 20 + [(45-20)(15+20)]/3
a) Writeln(` [(15+20)*(15+20) - 100]/ 2' , [(15+20)*(15+20) - 100]/2 ) ;
b) Writeln ('15+20 - (50+7)*(50+7)/5= ' , 15+20 - (50+7)*(50+7)/6 ) ;
c) Writeln ( ' 15 + 20 + (45-20)* (15+20)/3 = ' , 15+20 +(45-20)*(15+20)/3 );