Which equation shows the quadratic formula used correctly to solve 5x^2 + 3x - 4 = 0 for x?

Figure abcde is a regular pentagon. segment ae is located at a (2, 1) and e (4, 1). what is the perimeter of abcde? 4 units 6 units 8 units 10 units

What number should be added to the expression x^2+3x+ in order to create a perfect square trinomial? 3/2 3 9/4 9

Which of the following is the true for f(x) = 5cos