Slope intercept form for a line containing 4,2 that is parallel to the line y-2 = 3(x+7)

y-2 = 3(x+7) put it in y=mx+b form (slope intercept)

y-2 = 3(x+7) distribute 3

y-2 = 3x+21  add 2 to both sides

+2         +2

y = 3x + 23

so now the slope of that is 3 so the new equation has a slope of 3 because parallel slopes are equal.  

my new line has a slope of 3 and point (4,2)

so we use point slope formula y-y1 = m(x-x1)

y-2 =3(x-4) put it in y=mx+b form (slope intercept)

y-2 = 3(x-4) distribute 3

y-2 = 3x -12  add 2 to both sides

+2         +2

y = 3x + 10 which is you line slope intercept with parallel slope and contains (4,2)  

to find the total number of combinations, multiply the quantity of each item by each other:

2 pairs of shoes x 3 pairs of shorts = 6 different combinations.