Question 100596
4M-5=-8sqrt(M) ... squaring gives 16M^2-40M+25=64M


16M^2-104M+25=0 ... {{{M=(104 +- sqrt((-104)^2-4*16*25))/(2*16)}}} ... {{{M=(104 +- sqrt(9216))/32}}}


M=25/4 and M=1/4 ... sqrt can be +-