HCF and LCM of Algebraic Expression

Solve: A garden has plants that need watering every 12 days and others that need watering every 18 days. How often should the gardener water all the plants together?

• 36 days

• 42 days

• 30 days

• 24 days

A factory produces batches of products every 24 hours and another batch every 36 hours. How often do they produce a batch together?

• 48 hours

• 72 hours

• 30 hours

• 60 hours

L.C.M. of x² + x - 12 and x² - 9 is

• (x + 3)(x + 4)
• (x - 3)(x + 4)
• (x - 3)(x + 3)(x + 4)
• x - 3

Find the HCF by Factorization:

x³ - 27, x³ +6x-27, 2x² - 18

• 2x - 9
• x - 3
• x + 3
• x - 5

Find the LCM by Factorizing: x² + 4x +4 , x² - 4 , x² + x - 6

• (x+1)(x+4)(x-3)
• (x-2)(x+2)(x-3)
• (x+3)(x-3)(x-2)²

• (x+2)²(x-2)(x+3)

HCF of 18(x³ - 9x² + 8x) and 24(x² - 3x + 2) is

• 6(x-1)
• 12(x-3)
• 8(x-2)
• 4(x-1)

For what value of k for which the following expression will become a prefect square:
4x⁴ - 12x³ + 37x² - 42x + k

• 49
• 64
• 36
• 25

A school has classes that start every 20 minutes and others that start every 30 minutes. How often do all classes start together?

• 60 minutes

• 90 minutes

• 120 minutes

• 30 minutes