A = (20-2x)(10-2x) = 4(10-x)(5-x)
The roots are at x=5,10
But, for x > 5, 5-x < 0 which is not allowed
so, assuming an actual width of both the frame and the picture,
So, 0 < x < 5
A rectangular framed picture has a total length and width of 20 cm
20 cm and 10 cm, respectively. The frame has width x cm.
a Find the rule for the area (A cm ) of the picture inside.
b What are the minimum and maximum values of x?
1 answer
1 answer