Question
Solve the quadratic equation
Solve using the quadratic formula
Solve by completing the square
Solve using the PQ formula
x1=3−315,x2=3+315
Alternative Form
x1≈−8.61895,x2≈14.61895
Evaluate
x(1×3x×1−6)=42
Remove the parentheses
x×1×3x×1−6=42
Simplify
More Steps

Evaluate
x×1×3x×1−6
Any expression multiplied by 1 remains the same
x×1×3x−6
Rewrite the expression
x×3x−6
Multiply the terms
3x(x−6)
3x(x−6)=42
Rewrite the expression
31x2−2x=42
Move the expression to the left side
31x2−2x−42=0
Multiply both sides
3(31x2−2x−42)=3×0
Calculate
x2−6x−126=0
Substitute a=1,b=−6 and c=−126 into the quadratic formula x=2a−b±b2−4ac
x=26±(−6)2−4(−126)
Simplify the expression
More Steps

Evaluate
(−6)2−4(−126)
Multiply the numbers
More Steps

Evaluate
4(−126)
Multiplying or dividing an odd number of negative terms equals a negative
−4×126
Multiply the numbers
−504
(−6)2−(−504)
Rewrite the expression
62−(−504)
If a negative sign or a subtraction symbol appears outside parentheses, remove the parentheses and change the sign of every term within the parentheses
62+504
Evaluate the power
36+504
Add the numbers
540
x=26±540
Simplify the radical expression
More Steps

Evaluate
540
Write the expression as a product where the root of one of the factors can be evaluated
36×15
Write the number in exponential form with the base of 6
62×15
The root of a product is equal to the product of the roots of each factor
62×15
Reduce the index of the radical and exponent with 2
615
x=26±615
Separate the equation into 2 possible cases
x=26+615x=26−615
Simplify the expression
More Steps

Evaluate
x=26+615
Divide the terms
More Steps

Evaluate
26+615
Rewrite the expression
22(3+315)
Reduce the fraction
3+315
x=3+315
x=3+315x=26−615
Simplify the expression
More Steps

Evaluate
x=26−615
Divide the terms
More Steps

Evaluate
26−615
Rewrite the expression
22(3−315)
Reduce the fraction
3−315
x=3−315
x=3+315x=3−315
Solution
x1=3−315,x2=3+315
Alternative Form
x1≈−8.61895,x2≈14.61895
Show Solution
