Question 114044
7C(8C+7)=3C-15
56C^2+49C-3C+15=0
56C^2-46C+15=0
USING THE QUADRATIC EQUATION:
{{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}} WE GET:
C=(46+-SQRT[-46^2-4*56*15])/2*56
C=(46+-SQRT[2116-3360])/112
C=(46+-SQRT-1244)/112
C=(46+-35.37i)/112
C=46/112+35.37i/112
C=.41+.3158i ANSWER.
C=46/112-35.37i/112
C=.41-.3158i ANSWER.