a) 234 + 567 + 766 + 433

= (234 + 766) + (567 + 433)

= 1 000 + 1 000

= 2 000

b) 2 023 + 7 602 - 1 023 + 1 398

= (2 023 - 1 023) + (7 602 + 1 398)

= 1 000 + 9 000

= 10 000

c) 4 789 - 2 567 - 7 433 + 5 211

= (4 789 + 5 211) - (2 567 + 7 433)

= 10 000 - 10 000

= 0

c, 5 - 10 + 15 - 20 + 25 - 30 + 35 - 40 + 50 - 55 + 60 - 65 + 70

= 5 + (15 - 10) + (25 - 20) + (35 - 30) + (50 - 40) + (60 - 55) + (70 - 65)

= 5 + 5 + 5 + 5 + 10 + 5 + 5

= (5 + 5) + (5 + 5) + 10 + (5 + 5)

= 10 + 10 + 10 + 10

= 10 $\times$ 4

= 40

a,   234 + 567 + 766 + 433

= (234 + 766) + (567 + 433)

= 1000 + 1000

= 2000

b, 2023 + 7602 - 1023 + 1398

= (2023 - 1023) + (7602 + 1398)

= 1000 + 9000

= 10000

c, 4789 - 2567 - 7433 + 5211

= (4789 + 5211) - (2567 + 7433)

= 10000 - 10000

= 0

d, 5 - 10 + 15  - 20 + 25 - 30 + 35 - 40 + 50 - 55 + 60 - 65 + 70

= (70 -65) + (60 - 55) +(50 - 40) + (35  - 30) + (25 - 20) + (15 - 10) + 5

= 5 + 5 + 10 + 5 + 5  + 5  + 5

= 5 x 6 + 10

= 40 

a) 2000

b) 0

c) 40

a) \(x-\left(-234\right)=766\)

\(x=766+\left(-234\right)\)

\(x=532\)

b) \(2017-\left(17-x\right)=4016\)

\(17-x=2017-4016\)

\(17-x=\left(-1999\right)\)

\(x=17-\left(-1999\right)\)

\(x=2016\)

c) \(\left|x-1\right|=5\)

\(\left|x\right|=5+1\)

\(\left|x\right|=6\)

\(\Rightarrow x=6\)

d) \(\left(2x+1\right)^2=9\)

\(x=1\)

a) x= 0.2 = 1/5

b) x=2

a) 2009 : x -1009 : x = 5000

(2009 -1009) : x = 5000

1000 : x = 5000

x = 1/5.

b) 234 * x + 766 * x = 2000

( 234 + 766 ) * x = 2000

1000 * x = 2000 

x = 2

=  55331

= 1341

HỌC TỐT !

trả lời:

55331

1341

hok tốt nhé

tk mk nhé

54565+766=55331

575+766=1341

Học tốt nhé!

2757600 giây

766 giờ = 766 × 60 phút

= 45960 phút

= 45960 × 60 giây

= 2757600 giây

=1234 + 766 + 789 +211

=(1234 + 766) + (789 + 211)

= 2000 + 1000

= 3000

3000