Help please I don't know what the answer could be

answer: prime numbers are when u can multiply it only once. for example, when u   multiply 1*1 u get one nothing else can't multiply it to get one.

prime numbers: 1,2,3,5,7

lcm is finding the lowest common denominator. example, 2/20-1/10

10: 10,20

20: 20,40

both has the same number so do this.

2/20-1/20 and get 1/20

step-by-step explanation: