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For what value of x is PQ BC pls look at picture

For what value of x is PQ BC pls look at picture-example-1
User Mohamad
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2 Answers

1 vote
Let us assume PQ || BC.
Then, by Basic Proportionality Theorem, we get,
AP/PB = AQ/QC
=> x/(x+7) = (x-3)/(x+1)
=> x (x+1) = (x+7)(x-3)
=> x^2 + x = x^2 - 3x + 7x - 21
=> x = 4x - 21
=> -4x + x = -21
=> -3x = -21
=> 3x = 21
=> x = 21/3
=> x = 7
Therefore, for PQ||BC the value of x should be 7
User Edgars
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6.5k points
6 votes

Answer:

x = 7

Explanation:

According to the proportionality theorem of triangles, if a line parallel to one side of a triangle intersects the rest of the two sides, then the line divides these two sides proportionally.

So,
(AP)/(PB) = (AQ)/(QC)

Putting in the values to get:


(x)/(x+7) = (x-3)/(x+1)


x(x+1) = (x-3)(x+1)


x^2+x=x^2+7x-3x-21


7x-3x-x= 21


3x=21


x=7

Therefore, the value of
x in this case is equal to 7.

User Danott
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