The work of a student to solve the equation 2(6y − 3) = 20 + 6y is shown below:

step 1: 2(6y − 3) = 20 + 6y
step 2: 8y − 5 = 20 + 6y
step 3: 2y − 5 = 20
step 4: 2y = 25
step 5: y = 12.5

in which step did the student first make an error and what is the correct step?

step 2: 8y − 5 = 10 + 3y
step 2: 12y − 6 = 20 + 6y
step 3: 6y − 3 = 2(18 + 3y)
step 3: 2(6y − 3) = 18 + 3y

Kelly is a salesperson at a shoe store, where she must sell a pre-set number of pairs of shoes each month. at the end of each work day the number of pairs of shoes that she has left to sell that month is given by the equation s=300-15x , where s is the number of pair of shoes kelly still needs to sell and x is the number of days she has worked that month. what is the meaning of the number 300 in this equation

Adrawer contains 12 identical white socks, 18 identical black socks and 14 identical brown socks. what is the least number of socks you must choose, without looking, to be certain that you have chosen two socks of the same colour?

Which of the following is the result of expanding the series