Someone please help me !!

1!+2(2!)+3(3!)+...+n(n!)=(n+1)!-1

anyanavicka [17]

Step-by-step explanation:

OK, let's assume it this way:

Sn=1.1!+2.2!+3.3!+...+n.n!=(2‐1).1!+(3-1).2!+(4-1)3!+...+((n+1)-1).n!

Sn=1.1!+2.2!+3.3!+...+n.n!=(2‐1).1!+(3-1).2!+(4-1)3!+...+((n+1)-1).n!=(2.1!-1!)+(3.2!-2!)+(4.3!-3!)+...+((n-1)n!-n!)=(2!-1!)+(3!-2!)+(4!-3!)+

Sn=1.1!+2.2!+3.3!+...+n.n!=(2‐1).1!+(3-1).2!+(4-1)3!+...+((n+1)-1).n!=(2.1!-1!)+(3.2!-2!)+(4.3!-3!)+...+((n-1)n!-n!)=(2!-1!)+(3!-2!)+(4!-3!)+...+(n+1)!-n!=(n+1)!-1!=(n+1)!-1

and boom problem solved

7 0

2 years ago

your friend bought 3 bags of wild bird seed and an $18 bird feeder. each bag of birdseed costs the same amount. if your friend s

IrinaVladis [17]

The total amount that your friend spent is the sum of the cost for 3 bags of wild bird seed and the bird feeder. By letting x be the cost of each bag of wild bird seed, the total cost for purchasing 3 bags of this is 3x. The equation that may be used to determine x is letter "B. 3x + 18 = 45". Each bag costs $9.

8 0

3 years ago

Are 12/7 and 36/21 proportional

anastassius [24]

Answer:

Step-by-step explanation:

Cross multiply:

12 * 21 = 7 * 36

Simplifying

12 * 21 = 7 * 36

Multiply 12 * 21

252 = 7 * 36

Multiply 7 * 36

252 = 252

Add '-252' to each side of the equation.

252 + -252 = 252 + -252

Combine like terms: 252 + -252 = 0

0 = 252 + -252

Combine like terms: 252 + -252 = 0

0 = 0

Solving

0 = 0

Couldn't find a variable to solve for.

This equation is an identity, all real numbers are solutions.

(hope this helps can i plz have brainlist :D hehe)

5 0

3 years ago

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PLEASE HELP I NEED TO PASS “Solve for output, find f(x)=4x-3”

katrin2010 [14]

Answer:

-12

Step-by-step explanation:

6 0

3 years ago

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• Write an expression that is equivalent to 3(7 + x). 3(7 + x) + ? 2

maksim [4K]

Answer:

21+3x

Step-by-step explanation:

Expand this:

3(7+x)

So it becomes:

21+3x

3 0

3 years ago

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