Question 847253
{{{a*sqrt(b^2-c)=5k}}}
{{{4*sqrt(7^2-c)=5(11)}}}
{{{sqrt(49-c)=55/4}}}Divide by both sides by {{{4}}} 
{{{49-c=(55/4)^2}}}Square both sides
{{{49-c=3025/16}}}
{{{c=784/16-3025/16}}}Change 49 to a fraction with denominator of 16
{{{c=-2241/16}}}