Carl goes to the beach every third day and antonia goes every seventh day. how often do they see each other?

Carl and Antonia see other after every 21 days or after every three weeks.

Step-by-step explanation:

i) Carl goes to the beach every third day.

ii) Antonia goes to the beach every seventh day.

iii) the lowest common multiple of 3 and 7 is LCM(3,7) = 3 7 = 21

iv) therefore Carl and Antonia see other after every 21 days or after every three weeks.

step-by-step explanation:

ok so im not 100% sure but you would start by adding 5.1t and 1.9t beacuse they have the same variable. that is 7t.   then add -3.6 + 1.2 which is -2.4

so then keep that as -2.4 + 7t. i apologize if this is incorrect. best luck on your test < 3