find the lowest common multiple of 30,40 and 70?

Question

-|-8|- |-11-8|

Answer 1

30 = 3x10
40 = 4x10
70 = 7x10
So LCM = 3x4x7x10 = 840

-|-8|- |-11-8|
= -(8) - (19)
= - 27