Question

Answer 1

15:

a: \(x+5⋮x\)

=>\(5⋮x\)

=>\(x\in\left\{1;-1;5;-5\right\}\)

b: \(3x-4⋮x+1\)

=>\(3x+3-7⋮x+1\)

=>\(x+1\in\left\{1;-1;7;-7\right\}\)

=>\(x\in\left\{0;-2;6;-8\right\}\)

c: \(4x+2⋮x-2\)

=>\(4x-8+10⋮x-2\)

=>\(x-2\in\left\{1;-1;2;-2;5;-5;10;-10\right\}\)

=>\(x\in\left\{3;1;4;0;7;-3;12;-8\right\}\)

16:

a: \(2x^2+5⋮x\)

=>\(5⋮x\)

=>\(x\in\left\{1;-1;5;-5\right\}\)

b: \(x^2+x-3⋮x+1\)

=>\(x\left(x+1\right)-3⋮x+1\)

=>\(-3⋮x+1\)

=>\(x+1\in\left\{1;-1;3;-3\right\}\)

=>\(x\in\left\{0;-2;2;-4\right\}\)

c: \(2x^2-x+7⋮2x-1\)

=>\(x\left(2x-1\right)+7⋮2x-1\)

=>\(7⋮2x-1\)

=>\(2x-1\in\left\{1;-1;7;-7\right\}\)

=>\(x\in\left\{1;0;4;-3\right\}\)