Question 472213
u = {{{x^2 - 3x}}}
{{{7 - sqrt(u) = sqrt(u+5)}}}
Square both sides
{{{49 -14sqrt(u) + u = u + 5}}}
Subtract u on both sides
{{{49 -14sqrt(u) =  5}}}
Subtract 49 on both sides
{{{-14sqrt(u) = -44}}}
Divide by -14 on both sides
{{{sqrt(u) = 22/7}}}
Square both sides
{{{u = 484/49 = 9.877}}}
Replace u with equivalent expression
{{{x^2 - 3x = 9.877}}}
Set equation equal to zero
{{{x^2 - 3x - 9.877 = 0}}}
Use quadratic formula to solve for x: {{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}}
{{{x = (3 +- sqrt(9 - 4(-9.877)))/2}}}
{{{x = (3 +- sqrt(48.51))/2}}}
{{{x = (3 +- 6.965)/2}}}