Solve the equation. if necessary, round to the nearest tenth. 4x^2 =81 a 20.25, -20.25 b 2.25, -2.25 c 4.5 -4.5 d 9, -9

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).

The ksp expression for the system pbcl2(s) pb+2(aq) + 2 cl-(aq) is: [pbc12][pb+2][2cl-] [pb+2][cl-]2 [pb+2][2cl-]2 [pbcl2][pb+2][cl-]2 [pb+2][2cl-]2[pbcl2]

What effect would doubling all the dimensions of a triangular pyramid have on the volume of the pyramid? explain your reasoning.