82 - ( 15 + x ) = 92

15 + x = 82 - 92

15 + x = -10

x = ( -10 ) - 15

x = -25

82 - ( 15 + x ) = 92

         15 + x   = 82 - 92

          15 + x  = - 10

                  x  = - 10 - 15

                  x  = - 25

Vậy x = - 25

a,  13 2 = 169 < 216 = 13 2

b,  6 2 + 8 2 = 100 < 196 =  6 + 8 2

c,  13 2 - 9 2 = 88 > 16 =  13 - 9 2

d,  a 2 + b 2 <  a 2 + b 2 + 2 a b = a + b 2 a ; b ∈ N *

14x + 54 = 82

14x = 28

x = 2

175 + (30 - x) = 2001

30 - x = 1826

x = 30 - 1826

x = - 1796

1551 - 10 ( x + 1 ) = 55

10(x + 1) = 1496

x + 1 = 149,6

x = 148,6

5 . (x + 12) + 22 = 92

5 . (x + 12) = 70

x + 12 = 14

x = 2

6 . (x + 23) + 40 = 100

6 . (x + 23) = 60

x + 23 = 10

x = - 13

\(14x+54=82\)

\(\Leftrightarrow14x=82-54\)

\(\Leftrightarrow14x=28\)

\(\Leftrightarrow x=2\)

Vậy \(x=2\)

\(175+\left(30-x\right)=2001\)

\(\Leftrightarrow30-x=2001-175\)

\(\Leftrightarrow30-x=1826\)

\(\Leftrightarrow x=-1796\)

Vậy \(x=-1796\)

\(1551-10\left(x+1\right)=55\)

\(\Leftrightarrow10.\left(x+1\right)=1551-55\)

\(\Leftrightarrow10.\left(x+1\right)=1496\)

\(\Leftrightarrow x+1=\frac{1496}{10}\)

\(\Leftrightarrow x=\frac{1486}{10}\)

Vậy \(x=\frac{1486}{10}\)

\(5.\left(x+12\right)+22=92\)

\(\Leftrightarrow5.\left(x+12\right)=70\)

\(\Leftrightarrow x+12=14\).

\(\Leftrightarrow x=2\)

Vậy \(x=2\)

\(6.\left(x+23\right)+40=100\)

\(\Leftrightarrow6.\left(x+23\right)=60\)

\(\Leftrightarrow x+23=10\)

\(\Leftrightarrow x=-13\)

Vậy \(x=-13\)

\(-237\)

-237

1.  \(\text{5 + [- (-12) + (-9)] - [7 - (-10) + 3].}\)

\(=5+\left(12-9\right)-\left(7+10+3\right).\)

\(=5+3-20=-12.\)

2.  \(\text{(− 28) + (-35) - 92 + (-82).}\)

\(-28-35-92-82=-237.\)

a) <

b) <

c) >

d) <

<=> x -2 = 0

      x +9 =0

<=> x = 2 , x = -9 

Vậy .............

\(\left(x-2\right)\left(x+9\right)=0\\ \Rightarrow\left[{}\begin{matrix}x-2=0\\x+9=0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=2\\x=-9\end{matrix}\right.\)