-5/8 divided by -3/4 is the same as -5/8 multiplied by -4/3. Multiply the tops to get 20. Multiply the bottoms to get 24. A negative over a negative is positive and you end up with 20/24! :)
Trigonometry can be used to find angles and sides of simple triangles. If an 18-foot ladder touches a building 14 feet up the wall then the angle can be deduced by trigonometry. In this case, the ladder defines the hypotenuse (H) of the triangle and the wall defines the opposite (O) side of the triangle. Therefore we can use the equation theta=sin^-1(O/H) . This yields an angle of 51 degrees.
A. You can use y=mx+b to find the rate of change of a bushel corn in the current year. The rate of change would be y=8x.
B. One bushel is worth 8$ (24/3 = 8) in the current year, and in the previous year one bushel was worth 7$ (21/3= 7). Therefore there was a 1$ raise from the previous year to the current year.