Question

Bài 13 đề 5

Tính :

a) 23.25 + 75.23 - 1300

b) 36 : 3² - 5 . 2²

c) 183 + 80 : [ 20 - 4 ( 5² - 24 ) ]

d) (-125) - [148 + 5 . (-25) ]

Answer 1

a) 23.25 + 75.23 - 1300

= 23.(25 + 75) - 1300

= 23.100 - 1300

= 2300 - 1300

= 1000

b) 36 : 3² - 5.2²

= 36 : 9 - 5.4

= 4 - 20

= -16

c) 183 + 80 : [20 - 4.(5² - 24)]

= 183 + 80 : [20 - 4.(25 - 24)]

= 183 + 80 : (20 - 4.1)

= 183 + 80 : 16

= 183 + 5

= 188

d) (-125) - [148 + 5.(-25)]

= -125 - (148 - 125)

= -125 - 148 + 125

= (-125 + 125) - 148

= 0 - 148

= -148

Answer 2

a) 23.25 + 75.23 - 1300

= 23. (25+75) - 1300

= 23.100 - 1300

= 2300 - 1300 = 1000

b) 36 : 3² - 5 . 2²

= 36: 9 - 5.4

= 4 - 20 = -16

c) 183 + 80 : [ 20 - 4 ( 5² - 24 ) ]

= 183 + 80: [20 - 4.(25-24)]

= 183 + 80 : [20 - 4.1)]

= 183 + 80: [20 - 4]

= 183 + 80:16

= 183 + 5 = 188

d) (-125) - [148 + 5 . (-25) ]

= -125 - 148 + 125

= (125 - 125) - 148

= 0 - 148 = -148