Solve r (r-15)=47

Evaluate

r (r - 15) = 47

Expand the expression

More Steps

r^{2} - 15 r = 47

Move the expression to the left side

r^{2} - 15 r - 47 = 0

Substitute a= 1,b= - 15 and c= - 47 into the quadratic formula r = \frac{- b \pm b ^{2} - 4 a c}{2 a}

r = \frac{15 \pm ( - 15 ) ^{2} - 4 ( - 47 )}{2}

Simplify the expression

More Steps

r = \frac{15 \pm 413}{2}

Separate the equation into 2 possible cases

r = \frac{15 + 413}{2} r = \frac{15 - 413}{2}

Solution

r_{1} = \frac{15 - 413}{2}, r_{2} = \frac{15 + 413}{2}

Alternative Form

r_{1} \approx - 2.661201, r_{2} \approx 17.661201

Solve the quadratic equation