Respuesta :

Solution: For finding QR we need to apply Pythagoras Theorem

What is Pythagoras Theorem ?

ans : Pythagoras Theorem is the sum of square of two sides which is equal to the third side or the hypotenuse. This formula is valid oy incase of Right-Angled Traingle because one of three angles here is 90°

According to this law let's apply it in the diagram shown here.

  • (Hypotenuse)² = (Adjacent)² + (Opposite)²

  • (PR)² = (QR)² + (PQ)²

  • (5x - 2)² = (QR)² + (3x - 1)²

  • (QR)² = (5x - 2)² - (3x - 1)²

After factorising both of them we get

  • (QR)² = 25x² - 20x + 4 - (9x² - 6x + 1)

  • (QR)² = 25x² - 20x + 4 - 9x² + 6x - 1

  • (QR)² = 16x² - 14x + 3

  • QR = √(16x² - 14x + 3)

So, QR is √(16x² - 14x + 3)