a,(-12).x= 60-12

(-12).x=48

x=48:(-12)

x = -4

b,(-5).x + 5 = -24+6

(-5).x + 5 = 30

(-5).x      = 30-5

(-5).x      = 25

x = 25 : (-5)

x = -5

c,

$3x+36=-7x-64$

$10x=-100$

$x=-10$

$b,-5x-178=14x+145$

$-19x=323$

$x=-17$

\(\Leftrightarrow\left|x-1\right|=5\Leftrightarrow\left[{}\begin{matrix}x=5+1=6\\x=-5+1=-4\end{matrix}\right.\)

Vì  x chia 6 dư 4, chia 9 dư 7 nen ta có

            x+2 chia hết cho 6 và 9 

Suy ra x+2 thuộc BC(6,9)

Ta có 6=2.3                  suy ra BCNN(6,9)=2.3^2=18

          9=3^2

Vậy x+2 thuộc BC(6,9)={0;18;36;....}

       x thuộc {16;34;....}

Mà 30<x<100 nên x thuộc {36;70;88}

 Mình chi tinh duoc so 16 thôi .Còn may so khac thi chiu

\(\frac{3}{4}-\frac{5}{6}\le\frac{x}{12}< 1-\left(\frac{2}{3}-\frac{1}{4}\right)\)

\(\Leftrightarrow-\frac{1}{12}\le\frac{x}{12}< \frac{7}{12}\)

=> x \(\in\) {-1;0;1;2;3;4;5;6}

\(\frac{3}{4}-\frac{5}{6}\le\frac{x}{12}< 1-\left(\frac{2}{3}-\frac{1}{4}\right)\)

\(\Leftrightarrow\)\(\frac{9-10}{12}\le\frac{x}{12}< 1-\left(\frac{8-3}{12}\right)\)

\(\Leftrightarrow\)\(-\frac{1}{12}\le\frac{x}{12}< \frac{7}{12}\)

\(\Leftrightarrow-1\le x< 7\)

Mà x nguyên

=>x={-1;0;1;2;3;4;5;6}

1/4×2/6×3/8×4/10×...×14/30×15/32=1/2^x

<=>1/(2×2)×2/(2×3)×...×14/(2×15)×15/2^5=1/2^x

<=>1/2×1/2×...×1/2×1/(2^5)=1/2^x

<=>1/2^19=1/2^x=>x=19

Đề mình không ghi lại nhé.

^{\(\Rightarrow\frac{1\times2\times3\times4\times...\times14\times15}{4\times6\times10\times...\times30\times32}=\frac{1}{2^x}\)}\(\frac{1}{2^x}\)

\(\Rightarrow\frac{1\times2\times3\times4\times...\times14\times15}{2\times4\times6\times8\times10\times...\times30\times32}\)\(=\frac{1}{2^{x+1}}\)

\(\Rightarrow\frac{1}{2^{15}\times32}=\)\(\frac{1}{2^{x+1}}\)

\(\Rightarrow2^{15}\times2^5=2^{x+1}\)

\(\Rightarrow2^{20}=2^{x+1}\)

\(\Rightarrow x+1=20\Rightarrow x=19\)

Vậy \(x=1\)

Học tốt nhaaa!