Question

697:(15x+364):x=17

92.4-27=(x+350):x+315

720:(41-(2x-51)=2³.5

(x+1)+(x+2)+(x+3)+...+(x+100)=5750

Tìm x:

 

Answer 1

697:(15x+364):x=17

=> 15+360:x = 697:17=41

=> 360:x=41-15=26

=> x=360:26=180/13

 

92.4-27=(x+350):x+315

=> 1+350:x+315=341

=> 350:x = 341 -316=25

-> x=350:25=14

 

720:(41-(2x-51)=2³.5

=> 41-(2x-51)= 720 :40=18

=> 2x=41-18+51=74

=> x=74:2=37

 

(x+1)+(x+2)+(x+3)+...+(x+100)=5750

=>(x+x+...+x) +(1+2+3+..+99+100)=5750

=> 100.x +(100+1).100:2= 5750

=>100.x= 5750-5050=700

=> x=700:100=7

( L-i-k-e )

 

Answer 2

697 : (15x + 364) : x = 17

=> 15 + 360 : x = 697 : 17 = 41

=> 360 : x = 41 - 15 = 26

=> x = 360 : 26 = 180/13

92.4 - 27 = (x + 350) : x + 315

=> 1 + 350 : x + 315 = 341

=> 350 : x = 341 - 316 = 25

-> x = 350: 25 = 14

720 : (41 - (2 x - 51) = 2³.5

=> 41 - (2 x -51) = 720 : 40 = 18

=> 2x = 41 - 18 + 51 = 74

=> x = 74 : 2 = 37

(x + 1) + (x + 2) + (x + 3) +...+ (x + 100) = 5750

=>(x + x +...+ x) +(1 + 2 + 3 +...+ 99 + 100) = 5750

=> 100.x + (100 + 1).100 : 2 = 5750

=>100.x = 5750 - 5050 = 700

=> x = 700 : 100 = 7