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For a square ABCD, the side BC = 13 units.

A is at (.x, 8) and B is at (-7,3)
Also, x > 0.
Find.x​

1 Answer

6 votes

Answer:

x = 5

Explanation:

Since all the sides of a square is equal then AB = BC

Given BC = 13 units and A is at (.x, 8) and B is at (-7,3)

To get AB, we will find the distance between the two coordinates as shown;

AB = √(x₂-x₁)²+(y₂-y₁)²

AB = √(-7-x)²+(3-8)²

Since AB = BC, then AB = 13

13 = √(-7-x)²+(3-8)²

square both sides

13² = (√(-7-x)²+(3-8)²)²

169 = (-7-x)²+(3-8)²

169 = 49+14x+x²+(-5)²

169 = 49+14x+x²+25

169 = x²+14x+74

x²+14x+74-169 = 0

x²+14x+74-169 = 0

x²+14x-95= 0

x²+19x-5x-95= 0

x(x+19)-5(x+19) = 0

x-5 = 0 and (x+19) = 0

x = 5 and x = -19

Since x> 0, hence the value of x is 5

User Hdhruna
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