a) \(x\in\left\{1;-1;5;-5;7;-7;35;-35\right\}\)
b) \(x\in\left\{1;-1;3;-3;5;-5;15;-15\right\}\)
c) \(x\in\left\{0;25;50;75\right\}\)
d) Ta có: \(x+16⋮x+1\)
nên \(15⋮x+1\)
\(\Leftrightarrow x+1\in\left\{1;-1;3;-3;5;-5;15;-15\right\}\)
hay \(x\in\left\{0;-2;2;-4;4;-6;14;-16\right\}\)
a) 35 \(⋮\) x \(\Rightarrow\) x \(\in\) Ư(35) = {\(\pm1;\pm5;\pm7;\pm35\)}
b) 15 \(⋮\) x \(\Rightarrow\) x \(\in\) Ư(15) = {\(\pm1;\pm3;\pm5;\pm15\)}
c) x \(⋮\) 25 \(\Rightarrow\) x \(\in\) B(25) = {\(0;25;50;75;100;...\)}
Mà x < 100 \(\Rightarrow\) x \(\in\){\(0;25;50;75\)}
d) x + 16 \(⋮\) x + 1
\(\Rightarrow\) x + 16 - (x + 1) \(⋮\) x + 1
\(\Rightarrow\) 15 \(⋮\) x + 1
\(\Rightarrow\) x + 1 \(\in\) Ư(15) = {\(\pm1;\pm3;\pm5;\pm15\)}
\(\Rightarrow\) x \(\in\) {\(0;-2;2;-4;4;-6;14;-16\)}