Question

7 factorial supra 4 factorial plus 10 factorial supra 8 factorial

Answer 1

La prima fractie, scriem pe 7! in functie de 4!, iar pe 10 ! in functie de 8!$\frac{7!}{4!}+ \frac{10!}{8!} = \frac{4!*5*6*7}{4!} + \frac{8!*9*10}{8!}=210+90=300$

Answer 2

$\frac{7!}{4!}+\frac{10!}{8!}=$

$=\frac{1*2*3*4*5*6*7}{1*2*3*4}+\frac{1*2*3*4*5*6*7*8*9*10}{1*2*3*4*5*6*7*8}=$

$=5*6*7+9*10=$

$=5(42+18)=$

$=5*60=$

$=\boxed{300}$



$\boxed{n!=1*2*3*...*n}$