\(a)\)\(47-\left[\left(45.2^4-5^2.12\right)\div14\right]\)
\(=\)\(47-\left[\left(45.16-25.12\right)\div14\right]\)
\(=\)\(47-\left[\left(720-300\right)\div14\right]\)
\(=\)\(47-\left[420\div14\right]\)
\(=\)\(47-30\)
\(=\)\(17\)
\(b)\)\(10-\left[\left(8^2-48\right).5+\left(2^3.10+8\right)\right]\div28\)
\(=\)\(10-\left[\left(64-48\right).5+\left(8.10+8\right)\right]\div28\)
\(=\)\(10-\left[16.5+\left(80+8\right)\right]\div28\)
\(=\)\(10-\left[16.5+88\right]\div28\)
\(=\)\(10-\left[80+88\right]\div28\)
\(=\)\(10-168\div28\)
\(=\)\(10-6\)
\(=\)\(4\)
c) \(2345-1000:\left[19-2\left(21-18\right)^2\right]\)
= \(2345-1000:\left[19-2.3^2\right]\)
= \(2345-1000:\left[19-2.9\right]\)
= \(2345-1000:\left[19-18\right]\)
= \(2345-1000:1\)
= \(1345\)
\(c)\)\(2345-1000\div\left[19-2\left(21-18\right)^2\right]\)
\(=\)\(2345-1000\div\left[19-2.3^2\right]\)
\(=\)\(2345-1000\div\left[19-2.9\right]\)
\(=\)\(2345-1000\div\left[19-18\right]\)
\(=\)\(2345-1000\div1\)
\(=\)\(2345-1000\)
\(=\)\(1345\)
\(d)\)Bài này sai đề thì phải
\(177\div\left[2.\left(4^2-9\right)+3^2\left(16-10\right)\right]\)
\(=\)\(177\div\left[2.\left(16-9\right)+9.6\right]\)
\(=\)\(177\div\left[2.7+54\right]\)
\(=\)\(177\div\left[14+54\right]\)
\(=\)\(177\div68\)
\(=\)\(\frac{177}{68}\)
Nếu làm như thế này thì mình nghĩ sẽ đúng với đề bài hơn
\(177\div\left[2.\left(4^2-9\right)+3^2\left(15-10\right)\right]\)
\(=\)\(177\div\left[2.\left(16-9\right)+9\left(15-10\right)\right]\)
\(=\)\(177\div\left[2.7+9.5\right]\)
\(=\)\(177\div\left[14+45\right]\)
\(=\)\(177\div59\)
\(=\)\(3\)
