Question

The roots of the quadratic equation, x2 -9x +20 are

Answer 1

Answer:

x=5

x=4      

Step-by-step explanation:

x² -9x +20

a=1, b=-9, c=20

x=(-b± $\sqrt{(b×b)-4ac}$ )/2a

(the A means multiplication)

x=(-(-9)± $\sqrt{(-9×-9)-4(1)(20)}$ )/2(1)

x=(9± $\sqrt{81 -80)}$ )/2

x=(9± $\sqrt{1)}$ )/2

x=(9± 1)/2

x=(9+ 1)/2                      x=(9- 1)/2          

x=(10)/2                         x=(8)/2      

x=5                                x=4