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
