ZA and ZB are complementary angles. If m_A = (x +9)° and m ZB = (7x – 15)°, then find the measure of ZB.

The decibel level of sound is 50 db greater on a busy street than in a quiet room where the intensity of sound is watt/m2. the level of sound in the quiet room is db, and the intensity of sound in the busy street is watt/m2. use the formula , where is the sound level in decibels, i is the intensity of sound, and is the smallest sound intensity that can be heard by the human ear (roughly equal to watts/m2).

Which shows one way to determine the factors of 4x3 + x2 – 8x – 2 by grouping?

1. find the area of the unshaded square 2. find the area of the large square 3. what is the area of the frame represented by the shaded region show