Question

The length of the parallel sides of a trapezium are (x +3) cm and (x +9) cm. Given also that the height of the trapezium is (3x – 4) cm and that it has an area of 80 cm2, find the value of x.

Answer 1

Answer:

Step-by-step explanation:

area of  a trapezium=(h/2)(a+b)

80=(3x-4)(2x+12)/2

160=6x^2+36x-8x-48

160=6x^2+28x-48

6x^2+28x-208=0

1248=2*624=2*2*312=2*2*2*156=2*2*2*2*78=2*2*2*2*2*39=2*2*2*2*2*13*3

24,52

6x^2-24x+52x-208=0

6x(x-4)+52(x-4)=0

x=4