Question

ABCD is a rectangle. If AC = 2(5a + 1) and BD = 2(a + 1), find the length of each diagonal.

Answer 1

since the diagonals are equal,

2(5a+1) = 2(a+1)
10a+2 = 2a+2
a=0
I don't think so...

Answer 2

2(5a+1) = 2(a+1)
10a+2 = 2a+2
a=0

now you plug a back into the equation and you get 2 for both.