Pls asap ill give brainliest!

can someone solve this equation tell me how many solutions are possible.. and if there is none possible, how come?

-2(x+3) = -2x - 6

Ineed with number 17 i don’t get it at alll

One side of a rectangle is 7 feet shorter than seven times the other side. find the length of the shorter side if we also know that the perimeter of the rectangle is 306 feet.

On a string instrument, the length of a string varies inversely as the frequency of its vibrations. an 11-inch string has a frequency of 400 cylces per second. find the frequency of a 10-icnch string.