(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