Ascale drawing of an american flag is 10 inches long and 6 inches tall. the actual flag is 3 feet tall. what is the scale drawing?

The first thing that we must take into account is the following conversion:
 1 foot = 12 inches.
 Therefore, the current height of the flag is:
 (3) * (12) = 36 inches
 Then, the scale factor is:
 k = (6) / (36)
 k = 1/6
 
 the scale drawing is 1/6 of the current flag

1)  y is 15 less twice x
y= 2x - 15
2x - y = 15

2) x+y + 90 = 180
x+y = 90

System of equations:
x+y = 90
2x - y = 15

Answer is C.