(10x-3)²-8x=4(5x+3)²-403

(10x-3)²-8x=4(5x+3)²-403
100x-9-8x=4(25x+9)-403
100x-9-8x=100x+36-403
-9-8x=36-403
-8x=9+36-403
-8x=45-403
-8x=-358
8x=358
x=44.75