Answer:
Step-by-step explanation:
The area of a trapezium is given as;
Area = [tex]\frac{1}{2}[/tex](a + b)h
where: a is the length of the upper side, b is the length of its base and h is its height.
This implies that; a = x - 4, b = x + 5, h = 2x and area = 351
Thus,
351 = [tex]\frac{1}{2}[/tex]((x - 4) + (x + 50)) 2x
= (x - 4 + x + 5) x
531 = (2x + 1) x
= 2[tex]x^{2}[/tex] + x
So that;
2[tex]x^{2}[/tex] + x - 531 = 0
This gives a quadratic equation.