Đáp án:
\(1)\ 12.18+14.3-255:17=243\\ 2)\ 13+21.5-(198:11-8)=108\\ 3)\ 100-\left [60-(9-2)^{2} \right ].3^{2}=1\\ 4)\ 3^{2}.10^{3}-\left [13^{2}-(5^{2}.4+2^{2}.15) \right ].10^{3}=0\)
Giải thích các bước giải:
\(1/\\ 1)\ 12.18+14.3-255:17\\ =216+42-15\\ =243\\ 2)\ 13+21.5-(198:11-8)\\ =13+105-(18-8)\\ =13+105-10\\ =108\\ 3)\ 100-\left [60-(9-2)^{2} \right ].3^{2}\\ =100-(60-7^{2}).3^{2}\\ =100-(60-49).9\\ =100-11.9\\ =100-99\\ =1\\ 4)\ 3^{2}.10^{3}-\left [13^{2}-(5^{2}.4+2^{2}.15) \right ].10^{3}\\ =9.1000-\left [169-(25.4+4.15) \right ].1000\\ =9000-\left [169-(100+60) \right ].1000\\ =9000-(169-160).1000\\ =9000-9.1000\\ =9000-9000\\ =0\)
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