= 56 x 58 + 58 x 43 + 58+1

=58x[56 +43+1]

= 58 x100=

5800

56 x 58 + 58 x 43 + 58

= 56 x 58 + 58 x 43 + 58 x 1 

= ( 56 + 43 + 1 ) x 58

= 100 x 58

= 5800

56 x 58 + 58 x 43 + 58

= 58 x ( 56 + 43 + 1 )

= 58 x 100

=5800

-48

7,25 x (X + 56 ) = 58

x + 56 = 58 : 7,25 

x + 56 = 8

x = 8 - 56 

x = -48

12 x 35 x 56 x 58 = 34104000

12 x 25 x 35 x 5658 = 300 x 35 x 5658

                               = 10500 x 5658

                               = 59409000

Mik đàu tiên đấy , click cho mik nha !!!!!!!!!!!!!!!!!!

12 x 25 x 35 x5658 = 59409000

bằng-48

\(X=-48\)

X= 48

48 NHA BN

\(\left(\dfrac{x+1}{55}+\dfrac{x+2}{56}+\dfrac{x+3}{57}+\dfrac{x+4}{58}\right)-4=0\)

<=>\(\dfrac{x+1}{55}+\dfrac{x+2}{56}+\dfrac{x+3}{57}+\dfrac{x+4}{58}=4\)

<=>\(\dfrac{x+1}{55}-1+\dfrac{x+2}{56}-1+\dfrac{x+3}{57}+\dfrac{x+4}{58}-1=4-4\)

<=>\(\dfrac{x+1}{55}-\dfrac{55}{55}+\dfrac{x+2}{56}-\dfrac{56}{56}+\dfrac{x+3}{57}-\dfrac{57}{57}+\dfrac{x+4}{58}-\dfrac{58}{58}=0\)

<=>\(\dfrac{x-54}{55}+\dfrac{x-54}{56}+\dfrac{x-54}{57}+\dfrac{x-54}{58}=0\)

<=>\(\left(x-54\right)\left(\dfrac{1}{55}+\dfrac{1}{56}+\dfrac{1}{57}+\dfrac{1}{58}\right)=0\)

<=>x-54=0

<=>x=54

vậy phương trình có tập nghiệm là S={54}

=>\(\left(\dfrac{x+1}{55}-1\right)+\left(\dfrac{x+2}{56}-1\right)+\left(\dfrac{x+3}{57}-1\right)+\left(\dfrac{x+4}{58}-1\right)=0\)

=>x-54=0

=>x=54

Xin lỗi mình làm hơi tắt nha !!!Còn 1 cách nữa ,nếu bạn muốn thì nói với mình nha !!

Ta có : \(\frac{x-1}{59}+\frac{x-2}{58}+\frac{x-3}{57}=\frac{x-4}{56}+\frac{x-5}{55}+\frac{x-6}{54}\)

\(\Leftrightarrow\frac{x}{59}+\frac{x}{58}+\frac{x}{57}-\frac{x}{56}-\frac{x}{55}-\frac{x}{54}=\frac{1}{59}+\frac{2}{58}+\frac{3}{57}-\frac{4}{56}-\frac{5}{55}-\frac{6}{54}\)

<=> x = 60 

Vậy x = 60

Bạn kiểm tra lại đề nhé. Chỗ

\(.....=\frac{x-4}{56}+\frac{x-5}{56}+\frac{x-6}{54}\)

(x + 1)/58 + (x + 2)/57 = (x + 3)/56 + (x + 4)/55

(x + 1)/58 + 1 + (x + 2)/57 + 1 = (x + 3)/56 + 1 + (x + 4)/55 + 1

(x + 59)/58 + (x + 59)/57 = (x + 59)/56 + (x + 59)/55

=> (x + 59)/58 + (x + 59)/57 - (x + 59)/56 - (x + 59)/55 = 0

=> (x + 59).(1/58 + 1/57 - 1/56 - 1/55) = 0

Do 1/56 > 1/58; 1/55 > 1/57 => 1/58 + 1/57 - 1/56 - 1/55 khác 0

=> x + 59 = 0

=> x = -59

(x + 1)/58 + (x + 2)/57 = (x + 3)/56 + (x + 4)/55

(x + 1)/58 + 1 + (x + 2)/57 + 1 = (x + 3)/56 + 1 + (x + 4)/55 + 1

(x + 59)/58 + (x + 59)/57 = (x + 59)/56 + (x + 59)/55

=> (x + 59)/58 + (x + 59)/57 - (x + 59)/56 - (x + 59)/55 = 0

=> (x + 59).(1/58 + 1/57 - 1/56 - 1/55) = 0

Do 1/56 > 1/58; 1/55 > 1/57 => 1/58 + 1/57 - 1/56 - 1/55 khác 0

=> x + 59 = 0

=> x = -59

390625=5^{8  
chọn B}

B

b

Đáp án cần chọn là: B

x∈{−1;0;1;2;3;4;5}

5 6 + − 7 8 ≤ x 24 ≤ − 5 12 + 5 8 − 1 24 ≤ x 24 ≤ 5 24 − 1 ≤ x ≤ 5

- 7 8 + 5 6 < x 24 ≤ 5 8 + - 5 12

⇔ - 21 24 + 20 24 ≤ x 24 ≤ 15 24 + - 10 24 ⇔ - 1 24 ≤ x 24 ≤ 5 24

-1 ≤ x ≤ 5 mà x ∈ Z. Do đó: x ∈ { -1 ; 0 ; 1 ; 2 ; 3 ; 4 ; 5 }