\(x = {-b \pm \sqrt{b^2-4ac} \over 2a}\)

a, b: ở trên.

c. (x+1)+(x+3)+...+(x+97)+(x+99)=0 (có 50 cặp) 

=> x+1+x+3+...+x+97+x+99 = 0

=> (x+x+...+x)+(1+3+...+97+99)=0

=> 50x+\(\frac{\left(99+1\right).50}{2}\)=0

=> 50x+2500=0

=> 50x=-2500

=> x=-2500:50

=> x=-50

1/

(-2)² . 5² . (-27)

= 4 . 25 . (-27)

= 100 . (-27)

= -2700

2/

23 - (-x) = 24.

23 + x = 24

x = 24 - 23

x = 1.

1/(-2)².5².(-27)

=[(-2).5]²*(-27)

=[-10]²*(-27)

=100*(-27)

=-2700

2/23 - -x = 24

23+x=24

x=1

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38*x+24*x+x=4221

(38+24+1)*x=4221

63*x=4221

x=4221:63

x=67

\(\Leftrightarrow63x=4221\)

\(\Leftrightarrow x=67\)

Ai tích mk mk tích lại cho

gsyfdyfbfsyf

\(10\left(x-7\right)-8\left(x+5\right)=6.\left(-5\right)+24\)

\(\Leftrightarrow\)\(10x-70-8x-40=-6\)

\(\Leftrightarrow\)\(2x-110=-6\)

\(\Leftrightarrow\)\(2x=104\)

\(\Leftrightarrow\)\(x=52\)

Vậy...

10.(x-7)-8(x+5)=6.(-5)+24

=> 10.x - 10.7 - 8.x + 8.5 = -30 + 24

=> 10.x - 70 - 8.x + 40 = -6

=> (10.x - 8.x) - (70-40) = 6

=> 2.x - 30 = 6

=> 2.x = 6 + 30

=> 2.x = 36

=> x = 36 : 2

=> x = 18

<=> 10x-70-8x-40=-30+24

<=> 2x=70+40-30+24=104

=>x=52

Chị gái xinh đẹp à. Câu hỏi của chị khó quá ko ai trả lời. Thôi thì.......k cho mem đi😉

\(x+11\)\(⋮\)\(x+2\)

<=>   \(x+2+9\)\(⋮\)\(x+2\)

mà  \(x+2\)\(⋮\)\(x+2\)

=>  \(9\)\(⋮\)\(x+2\)

hay  \(x+2\)\(\inƯ\left(9\right)\)

đến đây tự lm tiếp