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Solve for x. assume that lines which appear tangent are tangent

Solve for x. assume that lines which appear tangent are tangent-example-1

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Answer:

x = 9

Explanation:

given two secants to a circle from an external point , then

the product of the measures of one secant's external part and that entire secant is equal to the product of the measures of the other secant's external part and that entire secant , that is

x(x + 21) = 10(10 + 17) ← distribute parenthesis

x² + 21x = 10 × 27 = 270 ( subtract 270 from both sides )

x² + 21x - 270 = 0 ← in standard form

(x + 30)(x - 9) = 0 ← in factored form

equate each factor to zero and solve for x

x + 30 = 0 ⇒ x = - 30

x - 9 = 0 ⇒ x = 9

however, x > 0 , then x = 9

User Katmanco
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