Question

[Đào Lê Tuấn Tú]

giup

Bài 1: Tính nhanh ( tính theo cách hợp lí)

9) 12 + 13 + 14 – 15 – 16 – 17;    11) 21 - 22 + 23 - 24;                   

 12) 125 - (115 - 99).                    13) 232 - (581 + 132 - 331);          

15) (56 - 27) - (11 + 28 - 16);        17)(-23) – 15 – (-23) + 5 + (-10).   1

8) 215 + (-38) – (-58) + 90 – 85 ;                      

19) 31 – [26 – (209 + 35)].                20) (-17) + 5 + 8 + 17;                    

21) 30 + 12 + (-20) + (-12);            22) (-4) + (-440) + (-6) + 440;       

23) (-5) + (-10) + 16 + (-1).             24) (+29) – (-25) + (+40) ;

25) (-30) –  (-5)  – (+3)     ;                26) (-24) + (-30) – (-40).

27) (+33) – (-46) + (-32) – (+15) ;     28) (-54) + (+39) – (+10) + (-85) ;

29) (-34)+ (-84)-(-54)+ (-1).               30) (1267 – 196) – (267 + 304) ;

31) (3965 – 2378) – (437 – 1378) – 528.

Answer 1

[♥ℒêღɦℴàทջღℒℴทջ︵²ᵏ⁸ ( ℱℐℛℰℳᎾUЅℰ )]

a) -75-(x+20)+95=0

<=> 20-(x+20)=0

<=> 20 - x - 20 = 0

<=> -x = 0

b) (135 + x ) -135 = 0

<=> 135 + x = 135

<=> x = 0

c)(-562) - ( x - 562 ) = 0

<=> -562 - x + 562 = 0

<=> x =0

d ) (61 + 9x -23) = 91

<=> 38+9x = 91

<=> 9x = 53

<=> x =\(\dfrac{53}{9}\)

h) 63-(51+3x) = 237 

<=> 63 - 51-3x = 237

<=> 12 - 3x = 237

<=> -3x = 225

<=> x = -75

làm tới đó hoi nha tự lực gánh sinh đi :))