HURRY PLZ

A system of equations is given below:

y = –2x + 1

6x + 2y = 22

Which of the following steps could be used to solve by substitution?

6x + 2(−2x + 1) = 22

−2x + 1 = 6x + 2y

6(−2x + 1) + 2y = 22

6(y = −2x + 1)

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

Prove sin2a + cos2a - 1 / sin2a + cos2a + 1 = 1 - tana / 1 + cota

Asix-sided number cube is rolled twice. what is the probability that the first roll is an even numbe and the second roll is a number greater than 4?