Giải Bài 1 trang 59

Đề bài

Thực hiện các phép tính sau:

a) $4.25-12.5+170:10$;

b) $\left(7+3^3:3^2\right).4-3$

c) $12:\left\{400:\left[500-\left(125+25.7\right)\right]\right\}$

d) $168+\left\{\left[2.\left(2^4+3^2\right)-{256}^0\right]:7^2\right\}$.

Lời giải chi tiết

a)

 4 . 25 – 12 . 5 + 170 : 10 

= (4 . 25) – (12 . 5) + (170 : 10) 

= 100 - 60 + 17 

= 40+17

= 57

b)

$\left(7+3^3:3^2\right).4-3$

$\begin{array}{c}=\left(7+3^{3-2}\right).4-3\\ =\left(7+3\right).4-3\\ =10.4-3\\ =40-3\\ =37\end{array}$

c)

12 : {400 : [500 – (125 + 25 . 7)]}

= 12 : {400 : [500 – (125 + 175)]}

= 12 : [400: (500 - 300)]

= 12 : (400: 200)

= 12 : 2

= 6

d)

 $168+\left\{\left[2.\left(2^4+3^2\right)-{256}^0\right]:7^2\right\}$

$\begin{array}{c}=168+\left[2.\left(16+9\right)-1\right]:49\\ =168+49:49\\ =168+1\\ =169\end{array}$