What decimal is represented by this expanded form.? 4×10,000+5×1,000+7×100+2×1+8×1/100+ 6×1/1000

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

Jack lives on a farm and has a large backyard. the area of his rectangular backyard is of a square mile. if the width of the yard is of a mile, what fraction of a mile is the length of the rectangular backyard?

Use set buikder notation to represent the following set: {, -2, -1, 0}