can anyone help me with this

Answer:
I only know how to do the LCM but thats it sorry
Step-by-step explanation:
I got this from the internet sorry if it dosen't help
LCM(84,90) = 1260
Answer:
HCF = 2 * 3
LCM = 2 *2 * 3 * 3 * 5 * 7
Step-by-step explanation:
A) 84 = 2 * 2 * 3 * 7
90 = 2 * 3 * 3 * 5
HCF = 2 * 3
B) 84 = 2 * 2 * 3 *7
90 = 2 * 3 * 3 * 5
LCM = 2 *2 * 3 * 3 * 5 * 7