We know that :
⊕ Area of a Rectangle is given by : Length × Width
Let us calculate the Area of the Rectangle in the Left side of the figure
⇒ Area of Left Rectangle : (x - 3) (x + 2x)
⇒ Area of Left Rectangle : (x - 3) (3x)
⇒ Area of Left Rectangle : 3x² - 9x
Let us calculate the Area of the Rectangle in the right side of the figure
⇒ Area of the Right Rectangle : (x - 1)(x)
⇒ Area of the Right Rectangle : x² - x
Given : Combined area of both rectangles is 50 cm²
⇒ 3x² - 9x + x² - x = 50
⇒ 4x² - 10x = 50
⇒ 2x² - 5x - 25 = 0
Comparing the above equation with ax² + bx + c = 0,
we can notice that :
→ a = 2
→ b = -5
→ c = -25
