Find the lcm (least common multiple) of 20 and 140.

The least common multiple of 20 and 140 would be 140.

$12. that is my answer.

option (b) is correct

step-by-step explanation:

to find the solution of this system, we need to convert it into reduced row-echelon form. we have,

after applying row operations r2 -> r2/2 and r3 -> r3/3, we get,