Can someone explain to me Linear Equations being equivalent? Why isn't x = -2 and x^2 = 4 equivalent? I don't understand why it is not. Additionally x = 7 and x^2 = 49 is also not equivalent and I cannot figure out why.

Thanks in advance!

Answer this two poles, ab and ed, are fixed to the ground with the of ropes ac and ec, as shown: two right triangles abc and edc have a common vertex c. angle abc and edc are right angles. ab is labeled 13 feet, ac is labeled 15 feet, ec is labeled 10 feet, and ed is labeled 4 feet.what is the approximate distance, in feet, between the two poles? 11.14 feet16.65 feet14.35 feet15.59 feet