Answer: -3(x^2 + 1)(x-5)
Explanation: -3x^3 + 15x+3x -15
Factor by grouping: -3x^2(x-5) +3(x-5)
Combine: (-3x^2 +3)(x-5)
Factor by GCF: -3(x^2 +1)(x-5)
Set equal to zero: (x^2 +1)=0
(x+5)=0
Solve: x=5, x=square root of 1
58 does not have a decimal place therefore it would be 58
QR is the median of the trapezoid, so its length is the average of the top and bottom bases. Write that. Say (length of QR)=1/2 of (length of the top + length of the bottom). That gives you a nice simple equation that you can easily solve for 'x'.
Complementary angels are two angles that equal 90 when added so S degrees + Z degree = 90 degrees or 50 degree + 40 degree = 90 so forth 4B in comments
