Area=1/2 times base times height note:bh=base times height
a=1/2bh b=width
h=-4+2w h=2w-4 subsitute a=1/2w(2w-4) a=1/2(2s^2-4w) a=w^2-2w a=63 63=w^2-2w subtract 63 from both sdies 0=w^2-2w-63 factor find what 2 numbers multiply to get -63 and add to get -2 the numbers are -9 and 7 so 0=(w-9)(w+7) if xy=0 then x and/or y=0
so w-9=0 w+7=0
solve each w-9=0 add 9 to both sdies w=9
w+7=0 subtract 7 from both sides w=-7 width cannot be negative so this can be discarded
