Make it better can't read it sorry
Either one at any given time could be equal to zero. So
x + 2 = 0
x = - 2
x - 18 = 0
x = 18
I've enclosed a graph of this so you can see that the answers I've given are the ones expected.
I think it is yz but I and not completely sure
Let the height of the rectangle = h
2b + 2h = 100
2(38) + 2h = 100
2h = 100 - 76
h = 12mm
area of rectangle = base x height
= 38 x 12
= 456mm²