Question

упростите выражение 19*42-42*16+16*40-40*13+13*38-38*10+10*36-36*7=

Answer 1

42×(19-16)+40×(16-13)+38×(13-10)+36×(10-7)=42×3+40×3+38×3+36×3= 3×(42+40+38+36) = 3×156=468