b)
624 - 120 +2025:(226-17×13)=
= 624-120+2025:(266-221)
= 624-120+2025:45
= 624-120+45
= 504+45
= 549
624 - 120 +2025:(226-17×13) = 549
c)
145+ 47× {215× 110 - 83 × (405- 18×16)}=
=145+47 × [215×110-83×(405-18×16)]
= 145+47×[215×110-83×(405-288)]
= 145+47×(23650-83×117)
= 145+47×(23650-9711)
= 145+47×13939
= 145+655133
= 655278
145+ 47× {215× 110 - 83 × (405- 18×16)}=655278
d)
512-287+10×{15+2×3+[105:15+(120-5×19)×10]×2}
= 512-287+10×{15+6+[7+(120-95)×10]×2}
= 512-287+10×[15+6+(7+25×10)×2]
= 512-287+10×(15+6+257×2)
= 512-287+10 × 535
= 225+5350
= 5575
512-287+10×{15+2×3+[105:15+(120-5×19)×10]×2} = 5575