Đáp án:
Giải thích các bước giải:
1.
a, -45 ; -12 ; -2 ; 12 ; 34
b, -111 ; -50 ; 0 ; 7 ; 102
c, -77 ; -23 ; -21 ; 23 ; 77
d, -2003 ; -45 ; 5 ; 19 ; 2004
2 .
a, $\frac{x}{5}$ = $\frac{2}{5}$
x = $\frac{2}{5}$ : $\frac{1}{5}$
x = 2
b, $\frac{3}{8}$ = $\frac{6}{x}$
3x = 6 . 8
3x = 48
x = 16
c, $\frac{1}{9}$ = $\frac{x}{27}$
x = $\frac{1}{9}$ : $\frac{1}{27}$
x = 3
d, $\frac{4}{x}$ = $\frac{8}{6}$
8x = 4. 6
8x = 24
x= 3
e , $\frac{3}{x-5}$ = $\frac{-4}{x+2}$
3 . (x+2) = -4 ( x-5 )
3x + 6 = -4x +20
3x + 4x = 20-6
7x = 14
x=2
f, $\frac{x}{-2}$ = $\frac{-8}{x}$
x. x = -8 . (-2)
x^2 = 16
=>\(\left[ \begin{array}{l}x=4\\x=-4\end{array} \right.\)
