Question

1.Tính nhanh:

a) 35.23+35.41+64.65

b)29.87-29.23+64.71

c)48.19+48.115+134.52

d)27.121-87.27+73.34

e)125.98-125.46-52.25

f)136.23+136.17-40.36

g)17.93+116.83+17.23

h)19.27+47.81+19.20

i)87.23+13.93+70.87

2.Tìm X:

a.[(6.x-39):7].4=12

b.(x:3-4).5=15

c.128-3.(x+4)=23

d.\(\left(3.x-3^4\right).7^3=2.7^4\)

x-[42+(-28)]=-8

g) x-7=-5

h) 15-5.(x+4)=-12-3

i) (7-x)-(25+7)=-25

k) 0:x=0

l) \(4^x=64\)

m) \(9^{x-1}=9\)

n) \(2^x:2^5=1\)

Answer 1

1. Tính nhanh:

a, 35.23+35.41+64.65

= 35. (23+41) +64.65

= 35. 64 + 64.65

= 64. ( 35 + 65 )

= 64 . 100

= 6400

b, 29.87 - 29.23 + 64.71

= 29.(87-23) + 64.71

= 29.64 + 64.71

= 64.(29 + 71)

= 64.100

= 6400

c, 48.19 + 48.115 + 134.52

= 48.(19 + 115) + 134.52

= 48.134 + 134.52

= 134.(48 + 52)

= 134.100

= 13400

d, 27.121 - 87.27 + 73.34

= 27.(121 - 87) + 73.34

= 27.34 + 73.34

= 34.(27 + 73)

= 34.100

= 3400

e, 125.98 - 125.46 - 52.25

= 125.(98 - 46) - 52.25

= 125.52 - 52.25

= 52.(125 - 25)

= 52.100

= 5200

f, 136.23 + 136.17 - 40.36

= 136.(23 + 17) - 40.36

= 136.40 - 40.36

= 40.(136 - 36)

= 40.100

= 4000

g, 17.93 + 116.83 + 17.23

= 17.(93+23) + 116.83

= 17.116 + 116.83

= 116.(17 + 83)

= 116.100

= 11600

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