Question

If the lcm of two numbers a and b is 40 what is the lcm of 7 a^2 and 7b^2

Answer 1

Answer:

11,200

Step-by-step explanation:

Given that the lcm of a and b  is 40 then a and b are factors of 40. All the multiples of 40 as sets are 1 and 40, 2 and 20, 4 and 10, 5 and 8. Of all these, only 5 and 8 would give a lcm of 40.

Let a = 5 and b = 8 as such,

7 a^2 = 7 * 5^2 = 175

7b^2 = 7 * 8^2 = 448

Then the lcm of 7 a^2 and 7b^2

= 11,200