Answer:
5.36
Step-by-step explanation:
Given that:
<BAD = <CAE, therefore, BD = EC
Let's take x to be the length of BD = EC
BD + DE + EC = BC
BC = 20,
BD = EC = x
DE ≈ 9.28
Thus,
x + 9.28 + x = 20
x + x + 9.28 = 20
2x + 9.28 = 20
Subtract 9.28 from both sides
2x + 9.28 - 9.28 = 20 - 9.28
2x = 10.72
Divided both sides by 2 to solve for x
BD ≈ 5.36
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Work Shown:
5x^3 + 14x^2 + 9x
x( 5x^2 + 14x + 9 )
To factor 5x^2 + 14x + 9, we could use the AC method and guess and check our way to getting the correct result.
A better way in my opinion is to solve 5x^2 + 14x + 9 = 0 through the quadratic formula
Then use those two solutions to find the factorization
x = -1 or x = -9/5
x+1 = 0 or 5x = -9
x+1 = 0 or 5x+9 = 0
(x+1)(5x+9) = 0
So we have shown that 5x^2 + 14x + 9 factors to (x+1)(5x+9)
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Overall,
5x^3 + 14x^2 + 9x
factors to
x(x+1)(5x+9)