Question
Solve the quadratic equation
Solve using the quadratic formula
Solve by completing the square
Solve using the PQ formula
z1=7−215,z2=7+215
Alternative Form
z1≈−0.745967,z2≈14.745967
Evaluate
z2−14z−11=0
Substitute a=1,b=−14 and c=−11 into the quadratic formula z=2a−b±b2−4ac
z=214±(−14)2−4(−11)
Simplify the expression
More Steps

Evaluate
(−14)2−4(−11)
Multiply the numbers
More Steps

Evaluate
4(−11)
Multiplying or dividing an odd number of negative terms equals a negative
−4×11
Multiply the numbers
−44
(−14)2−(−44)
Rewrite the expression
142−(−44)
If a negative sign or a subtraction symbol appears outside parentheses, remove the parentheses and change the sign of every term within the parentheses
142+44
Evaluate the power
196+44
Add the numbers
240
z=214±240
Simplify the radical expression
More Steps

Evaluate
240
Write the expression as a product where the root of one of the factors can be evaluated
16×15
Write the number in exponential form with the base of 4
42×15
The root of a product is equal to the product of the roots of each factor
42×15
Reduce the index of the radical and exponent with 2
415
z=214±415
Separate the equation into 2 possible cases
z=214+415z=214−415
Simplify the expression
More Steps

Evaluate
z=214+415
Divide the terms
More Steps

Evaluate
214+415
Rewrite the expression
22(7+215)
Reduce the fraction
7+215
z=7+215
z=7+215z=214−415
Simplify the expression
More Steps

Evaluate
z=214−415
Divide the terms
More Steps

Evaluate
214−415
Rewrite the expression
22(7−215)
Reduce the fraction
7−215
z=7−215
z=7+215z=7−215
Solution
z1=7−215,z2=7+215
Alternative Form
z1≈−0.745967,z2≈14.745967
Show Solution
