Ascale drawing of a bedroom is shown below. the scale is 1 : 30.

show your work to determine the area of the room in square feet.

We know  that
[scale]=1 in / 30 in
scale=measure in the drawing/measure in the actual
[measure in the actual]=measure in the drawing/scale

the measure in the drawing are
3 in x 4 in
so
for 3 in
measure in the drawing=3 in
[measure in the actual]=3/(1/30)> 3*30> 90 in

for 4 in
measure in the drawing=4 in
[measure in the actual]=4/(1/30)> 4*30> 120 in

the measure in the actual are
90 in x 120 in

1 ft> is equal to 12 in
 x> 90 in
x=90/12> 7.5 ft

1 ft> is equal to 12 in
 x> 120 in
x=120/12> 10 ft

the measure of a bedroom in feet are
7.5 ft x 10 ft

the area=7.5*10> 75 ft²

the answer is
the area of the room is 75 ft²

If you make it a little more clear i can answer it