Answer:
y=15
x=43
(any variable can be used, I used x and y to make it easier to show)
Step-by-step explanation:
x+y=58
x-y=28
get x by its self
x=58-y
then subsitute into the other equation
(58-y)-y=28
58-2y=28
-2y=-30
y=15
sub. again
x+15=58
x=43
Recall that A = 1/2bh.
We are given that h = 4+2b
So, putting it all together:
168 = 1/2 b(4+2b)
168 = 1/2(4b + 2b^2)
168 = 2b + b^2
b^2 + 2b - 168 = 0.
Something that multiplies to -168 and adds to 2? There's a trick to this.
Notice 13^2 = 169. So, it's more than likely in the middle of the two numbers we're trying to find. So let's try 12 and 14. Yep. 12 x 14 = 168. So this factors into (b+14)(b-12) So b = -14 or b =12. Is it possible to have a negative length on a base? No. So 12 must be our answer.
Let's check this. If 12 is our base, then according to our problem, 2*12 + 4 would be our height... or 28. so what is 12 * 28 /2?
196. Check.
Hope this helped!
Hdhhdhzhzhzj on da guys you welcome
BDE are the correct options
