Solve 42b^21 - 39b = 24

Question

Solve the quadratic equation

Solve using the quadratic formula

Solve by completing the square

Solve using the PQ formula

b_{1} = \frac{13 - 617}{28}, b_{2} = \frac{13 + 617}{28}

Alternative Form

b_{1} \approx - 0.422839, b_{2} \approx 1.35141

Evaluate

42 b^{2} \times 1 - 39 b = 24

Multiply the terms

42 b^{2} - 39 b = 24

Move the expression to the left side

42 b^{2} - 39 b - 24 = 0

Substitute a= 42,b= - 39 and c= - 24 into the quadratic formula b = \frac{- b \pm b ^{2} - 4 a c}{2 a}

b = \frac{39 \pm ( - 39 ) ^{2} - 4 \times 42 ( - 24 )}{2 \times 42}

Simplify the expression

b = \frac{39 \pm ( - 39 ) ^{2} - 4 \times 42 ( - 24 )}{84}

Simplify the expression

More Steps

b = \frac{39 \pm 5553}{84}

Simplify the radical expression

More Steps

b = \frac{39 \pm 3 617}{84}

Separate the equation into 2 possible cases

b = \frac{39 + 3 617}{84} b = \frac{39 - 3 617}{84}

Simplify the expression

More Steps

b = \frac{13 + 617}{28} b = \frac{39 - 3 617}{84}

Simplify the expression

More Steps

b = \frac{13 + 617}{28} b = \frac{13 - 617}{28}

Solution

b_{1} = \frac{13 - 617}{28}, b_{2} = \frac{13 + 617}{28}

Alternative Form

b_{1} \approx - 0.422839, b_{2} \approx 1.35141

Show Solution