Answer:
x= -2-√11. or. x= -2 + √11
Step-by-step explanation:
solving quadratic equation by completing the square
x^2+4x-7=0
x^2+4x=7
x^2+4x + (4/2)^2=7 + (4/2)^2 ( adding (1/2 coefficient of x)^2 on both sides
x^2+4x + 4=7 + 4
x^2+4x + 4=11. factorize(x^2+4x + 4) into (x + 2)^2
(x + 2)^2=11
√(x + 2)^2= + - √11
x + 2 = + - √11
there are two different solution .
x + 2 = -√11. or x + 2 = + √11.
x= -2-√11. or. x= -2 + √11.
<h3>
Answer: 40 inches</h3>
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Explanation:
- x = first piece
- 2x = second piece, since its twice as long as the first
- 5x = third piece, since its five time as long as the first
x is some positive real number, and the units of each are in inches.
Add up the smaller pieces and we should get 64 inches back again
x+2x+5x = 64
8x = 64
x = 64/8
x = 8
The first piece is 8 inches long.
2x = 2*8 = 16 is the length of the second piece (in inches)
The third piece is 40 inches because 5x = 5*8 = 40
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Summary:
first = 8 inches
second = 16 inches
third = 40 inches
Check: 8+16+40 = 64, which confirms the answer
Tsquare= Ksquare +Vsquare -2(K)(V) times cosT
