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3 years ago

5

Slove x^2-8x=20 by completing the square. which is the solution set of equation?

1 answer:

sveticcg [70]3 years ago

3 0

x^2-8x=20

Move +20 to the other side. Sign changes from +20 to -20

x^2-8x-20=20-20

x^2-8x-20=0

Think about two numbers that equals to -20 and -8.

(x-10)(x+2)=0

x-10=0 ( move -10 to the other side). Sign changes from -10 to 10

x-10+10=0+10

x=10

x+2=0 ( move +2 to the other side). Sign changes from +2 to -2

x+2-2=0-2

x=-2

Answer:

x=10, x=-2

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$a_{n+1} = (a_{n-2} + 2(n-1)) + 2((n+1)+n) \\ ~~~~~~~ = a_{n-2} + 2 ((n+1) + n + (n-1))$

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and so on down to

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balu736 [363]

Answer:

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Step-by-step explanation:

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