First simplify this inequality:

Now you can graph this inequality. Draw the vertical dashed line x=3 and shade the region to the right from this line. This is exactly the region that represents the solution of inequality (see attached diagram for details).
810
.....+27+31+35+39+43+47+51+55+59+63+67+71+75+79
Any value you choose for x will make the equation a TRUE statement. This type of equation is called an identity, and the solution set is all real numbers.
We have to calculate the suface of the four walls and the ceiling.
Surface of the four walls=2(10 ft * 10ft ) + 2(12 ft * 10 ft)=200 ft² + 240 ft²=
=440 ft²
Surface of the ceiling=10 ft * 12 ft=120 ft²
Total surface=440 ft² + 120 ft²=560 ft²
Now, we have to caluclate the number of gallons of paint.
1 gallon------------------------400 ft²
x----------------------------------560 ft²
x=(1 gallon * 560 ft²) / 400 ft²=1.4 gallons.
answer: Ryan need to paint all four walls and the ceiling 1.4 gallons.