(1) 1/4+6/(y+2)=6/y, multiply through by 4y(y+2):
y(y+2)+24y=24(y+2),
y2+2y+24y=24y+48,
y2+2y-48=0=(y+8)(y-6) so y=-8 or 6.
(2) b=3abx2-5x,
3abx2-5x-b=0. Applying the formula:
x=(5±√(25+12ab2))/(6ab).
(3) p(x)=-x2-8x-12=-(x2+8x+12)=-(x2+8x+16-4) or -(x+2)(x+6),
p(x)=-((x+4)2-4)=4-(x+4)2. The right-hand side has a maximum value of 4 when x=-4, so the vertex is at (-4,4), and the graph is an upside down parabola. x-intercept is when y=p(x)=0=-(x+2)(x+6). 2 x-intercepts: (-2,0) and (-6,0). y-intercept when x=0 so (0,-12) is the y-intercept.
