-4, square root of 28x times square root of 7x^3

Can you simplify 4/7? 24 points will be awarded!

After being rearranged and simplified, which of the following equations could be solved using the quadratic formula? check all that apply. a. 9% + 3x2 = 14 + x-1 b. -x+ + 4x + 7 = -32-9 c. 5x + 4 = 3x4 - 2 d. 2x2 + x2 + x = 30

Which expression can be used to determine the slope of the line that passes through the points -6, three and one, -9