cậu dịch ra cho tớ nha. rồi tớ giải cho.

c: =30 năm 54 tháng

=33 năm 6 tháng

d: =9h60'=10h

e: =568s-59s=509s

f: =14 giờ 322 phút

=19h22'

\(\text{a)}350:\left[19-\left(7x-3\right)\right]=350\)

\(\Rightarrow19-\left(7x-3\right)=1\)

\(\Rightarrow19-7x+3=1\)

\(\Rightarrow-7x=-21\)

\(\Rightarrow x=3\)

\(\text{b)}7.\left[109-\left(x-9\right)\right]-420=0\)

\(\Rightarrow7\left(109-x+9\right)=420\)

\(\Rightarrow118-x=60\)

\(\Rightarrow x=58\)

\(\text{c)}252-2\left\{200-4\left[90-7.\left(19-9\right)\right]\right\}.x=4\)

\(\Rightarrow2\left\{200-4\left[90-7.10\right]\right\}.x=250\)

\(\Rightarrow\left[200-4\left(90-70\right)\right].x=125\)

\(\Rightarrow\left[200-4.20\right].x=125\)

\(\Rightarrow120x=125\)

\(\Rightarrow x=\frac{125}{120}=\frac{25}{24}\)

\(\text{Xin điểm ạ}\)

350:[19-(7x-3)]=350

[19-(7x-3)]=350:350

[19-(7x-3)]=1

(7x-3)=19-1

(7x-3)=18

7x=18+3

7x=21

x=21:7

x=3

vậy x=3

7.[109-(x-19)]-420=0

7.[109-(x-19)]=0+420

7.[109-(x-19)]=420

[109-(x-19)]=420:7

[109-(x-19)]=60

(x-19)=109-60

(x-19)=49

x=49+19

x=58

vậy x=58

254-2{200-4.[90-7.(19-9)]}.x=4

254-2{200-4.[90-7.10]}.x=4

254-2{200-4.[90-70]}.x=4

254-2{200-4.20}.x=4

254-2{200-80}.x=4

254-2.120.x=4

254-240.x=4

240.x=254-4

240.x=250

x=250:240

x=25/24

vậy x=25/24

\(x\in BC\left(9,12,18\right)=B\left(36\right)=\left\{0;36;72;108;144;...\right\}\)

Mà \(80< x< 109\Rightarrow x=108\)

A

A