Приведите к знаменателю 6/b-4 к знаменателю 1)5b-20 2)12-3b3)b в квадрате -4b4)b в квадрате -16

1)

[tex]\tt \dfrac{6}{b-4} ^{(5} =\dfrac{5\cdot 6}{5\cdot (b-4)} =\dfrac{30}{5b-20}[/tex]

2)

[tex]\tt \dfrac{6}{b-4} ^{(\, (-3)} =\dfrac{-3\cdot 6}{-3\cdot (b-4)} =\dfrac{-18}{12-3b}[/tex]

3)

[tex]\tt \dfrac{6}{b-4} ^{(b} =\dfrac{b\cdot 6}{b\cdot (b-4)} =\dfrac{6b}{b^2-4b}[/tex]

4)

[tex]\tt \dfrac{6}{b-4} ^{(\, (b+4)} =\dfrac{(b+4)\cdot 6}{(b+4)\cdot (b-4)} =\\ \\ =\dfrac{6b+24}{b^2-4^2} =\dfrac{6b+24}{b^2-16}[/tex]

[tex]\displaystyle 1).\;\;\;\frac{6}{b-4} = \frac{5*6}{5(b-4)} =\frac{30}{5b-20}\\\\\\ 2).\;\;\; \frac{6}{b-4} =-\frac{6}{(4-b)} = -\frac{3*6}{3*(4-b)} = -\frac{18}{12-3b}\\\\\\3).\;\;\; \frac{6}{b-4} =\frac{6b}{(b-4)b} =\frac{6b}{b^2-4b} \\\\\\4).\;\;\; \frac{6}{b-4} = \frac{6(b+4)}{(b-4)(b+4)} = \frac{6b+24}{b^2-16}[/tex]