Question

Rewrite the function by completing the square r^2+18x+80=0

Answer 1

x+9^2=1

Explanation:

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Answer 2

x = -10, -8

Explanation:

x^2+18x+80=0

Subtract 80 from each side

x^2+18x=-80

Take the coefficient of x

18

Divide by 2

18/2 = 9

Square it

9^2 =81

Add 81 to each side

x^2+18x +81=-80+81

(x+ 9) ^2 = 1

Take the square root of each side

sqrt((x+ 9) ^2 )=±sqrt( 1)

x+9 = ±1

Subtract 9 from each side

x+9-9= -9 ±1

x = -9+1 x = -9-1

x = -8 x = -10