Find the value of x?

Question

1/5!+1/6!=x/7!

Answer 1

Multiply through by 7!: 7*6+7=x, so x=49.

Comments

Is there any different method to Solve this?

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Yes. You can convert the factorials into numbers; 5!=120, 6!=720, 7!=5040.

1/5!+1/6!=(6+1)/6!=x/7!

7/6!=x/7! But 7!=7*6!, so 7/6!=x/(7*6!) and x=7*7*6!/6!=7*7=49.

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My problem is how did u get (6+1)/6! Where from the 1?pls

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It's because 6!=6*5! So 1/5!+1/6!=1/5!+1/6*5! = (1/5!)(1+1/6)=(1/5!)(6+1)/6=(1/6*5!)(6+1)=(6+1)/6!=7/6!.