No because
15b + 4 = 25.6
15b = 21.6
b = 1.44
0.6+15b+4 = 25.6
4.6 + 15b = 25.6
15b = 21
b = 1.4
The answers are not the same therefore they are not equivalent.
There are 108 degrees in each interior angle of a regular pentagon .
I hope that's help !
3x^2 -6x + 6 :) hope this is alright