X- 7 = 5x - 21 can anyone answer this? i came up with x= 2.8 is that right? if not, how would you do it?

Determine which expressions represent real numbers and which expressions represent complex number. asaaap! plis!

When george started his current job, his employer told him that at the end of the first year, he would receive two vacation days. after each year worked, his number of vacation days will double up to five work weeks (25days) of payed vacation. how many vacation days will he have in 4 years

How many 3-digit numbers can you write using only digits 1 and 7? (of course, digits can repeat.) how many 3-digit numbers can you write using only digits 1 and 7? (of course, digits can repeat.)