Answer:
C
Step-by-step explanation:
Factor, where possible the expressions on the numerators/ denominators
3x - 21 = 3(x - 7) ← common factor of 3
x² + 3x = x(x + 3) ← common factor of x
7x - 49 = 7(x - 7) ← common factor of 7
The rational expression can now be written as
[tex]\frac{3(x-7)}{x}[/tex] × [tex]\frac{x(x+3)}{7(x-7)}[/tex]
Cancelling the factors x, x - 7 on the numerator/denominator leaves
[tex]\frac{3(x+3)}{7}[/tex] → C
