Maria can bake a cake for the cost of C dollars. She marks up her cakes by 90% so that she can make a profit. If she sells 15 cakes, it can be modeled by this
expression: 15(C + .9C). Which of these are true? Mark all that apply.*

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).

In trapezoid efgh, m∠hef=(4x2+16)∘ and m∠gfe=(5x2+12)∘. find the value of x so that efgh is isosceles.

Rewrite the following quadratic functions in intercept or factored form. show your work. y = 4x^2 - 19x- 5