Work out the value of 23 - 4b. When b = 3

3(10x-y)-5(x-y^2) need this solved asap

How can we find the measure of an exterior angle if we know the measurement of an interior angle

The area of a 25-inch tv screen is 300 square inches. the area of a 40-inch tv screen is 768 square inches. the are of the smaller screen is what percent of the area of the larger screen?