1) Begin by expanding the squares and distributing the coefficients:

(6x+1)^2 + 2(6x+1) - 24 = 0
(36x^2 + 12x + 1) + (12x + 2) - 24 = 0
36x^2 + 12x + 1 + 12x + 2 - 24 = 0
36x^2 + 24x - 21 = 0

2) Similarly, expand the squares and distribute the coefficients:

8(10-3x)^2 - 5(10-3x) - 3 = 0
8(100 - 60x + 9x^2) - 5(10) + 15x - 3 = 0
800 - 480x + 72x^2 - 50 + 15x - 3 = 0
72x^2 - 465x + 747 = 0

These are the simplified forms of the quadratic equations.