A) [(3×-2) ×2/3+1/2] × 6/3 =3
B) 375-(a-25)=300
375- B =300
B=375-300
B=75
a-25=75 (B)
a=75+25
a=100
B= a-25
C) 1+2+3+4+5...=55
1+2+3+4+5+6+7+8+9+10=55
