$\frac{ 3{a}^{3}{c}^{n} }{ 7{x}^{3}{b}^{n} } \times \frac{ 49{x}^{n-1}{b}^{n+2} }{ 9{a}^{n+5}{c}^{n+1} } \times \frac{ {a}^{2}{x}^{4} }{ c }$
Cancel out the greatest common factor $7$$\frac{ 3{a}^{3}{c}^{n} }{ {x}^{3}{b}^{n} } \times \frac{ 7{x}^{n-1}{b}^{n+2} }{ 9{a}^{n+5}{c}^{n+1} } \times \frac{ {a}^{2}{x}^{4} }{ c }$
Cancel out the common factor ${b}^{n}$$\frac{ 3{a}^{3}{c}^{n} }{ {x}^{3} } \times \frac{ 7{x}^{n-1}{b}^{2} }{ 9{a}^{n+5}{c}^{n+1} } \times \frac{ {a}^{2}{x}^{4} }{ c }$
Cancel out the greatest common factor $3$$\frac{ {a}^{3}{c}^{n} }{ {x}^{3} } \times \frac{ 7{x}^{n-1}{b}^{2} }{ 3{a}^{n+5}{c}^{n+1} } \times \frac{ {a}^{2}{x}^{4} }{ c }$
Cancel out the common factor ${a}^{3}$$\frac{ {c}^{n} }{ {x}^{3} } \times \frac{ 7{x}^{n-1}{b}^{2} }{ 3{a}^{n+2}{c}^{n+1} } \times \frac{ {a}^{2}{x}^{4} }{ c }$
Cancel out the common factor ${c}^{n}$$\frac{ 1 }{ {x}^{3} } \times \frac{ 7{x}^{n-1}{b}^{2} }{ 3{a}^{n+2}c } \times \frac{ {a}^{2}{x}^{4} }{ c }$
Cancel out the common factor ${x}^{3}$$\frac{ 7{x}^{n-1}{b}^{2} }{ 3{a}^{n+2}c } \times \frac{ {a}^{2}x }{ c }$
Cancel out the common factor ${a}^{2}$$\frac{ 7{x}^{n-1}{b}^{2} }{ 3{a}^{n}c } \times \frac{ x }{ c }$
Multiply the fractions$\frac{ 7{b}^{2}{x}^{n} }{ 3{a}^{n}{c}^{2} }$