Question

find roots of the quadratic equations
k²-12k-20=0​

Answer 1

Answer: PLEASE BRAINLIEST MY ANSWER

k  = 6±2√14

Step-by-step explanation:

Q) Find roots of the quadratic equations  k²-12k-20=0​

⇒Given, k²-12k-20=0​

∵ we know that the formula for finding the roots of quadratic equation-

ak²+bk+c=0  ⇔  k = [-b±√(b²-4ac)] / 2a

comparing k²-12k-20=0 with ax²+bx+c=0

∵ a=1, b=-12, c=-20

∴ k = {-(-12)±√[(-12)²-4×1×(-20)]} / 2×1

     = {12±√[144+80]} / 2

     = {12±√[224]} /2

     = {12±√[14×16]} / 2

     = {12±4√14} / 2

     = {2×[6±2√14]} / 2

 k  = 6±2√14