Question

Pls solve Q20 with proper steps

Answer 1

Answer:

10

Step-by-step explanation:

Given:  Area of circle = 9πx² - 12πx + 4π = π(9x² - 12x + 4)

We know that Area of circle = πr²

⇒ πr² = π(9x - 12x + 4)

⇒ r² = 9x² - 12x + 4

⇒ r² = (3x - 2)²

⇒ r = 3x - 2.

When x = 4:

⇒ r = 3(4) - 2

     = 12 - 2

     = 10 .

Therefore, radius of the circle is 10 cm.

Hope it helps!

Answer 2

Answer:

10

Step-by-step explanation:

Area of circle = 9πx² - 12πx + 4π

= π(9x² - 12x + 4)

Area of circle = πr²

πr² = π(9x - 12x + 4)

r² = 9x² - 12x + 4

r² = (3x - 2)²

r = 3x - 2.

When x = 4:

r = 3(4) - 2

12 - 2

10 .

Therefore, radius of the circle is 10 cm.