Question

HURRY UP PLEASE !!

5 x 2 - 21 = 39 ; Solve and what are the x-intercepts of this quadratic equation ?

Answer 1

The x-interecepts are 5.6 and -1.4, approximately.

Explanation:

The given equation is

`5x^(2) -21x=39`

Where
`a=5`,
`b=-21` and
`c=39`, let's use the quadratic formula

`x_(1,2)=\frac{-b(+-)\sqrt{b^(2)-4ac } }{2a} =\frac{-(-21) (+-)\sqrt{(-21)^(2) -4(5)(-39)} }{2(5)}\\ x_(1,2)=(21(+-)√(441+780) )/(10)=(21(+-35))/(10)\\x_(1)=(21+35)/(10)=(56)/(10) \approx 5.6\\ x_(2)=(21-35)/(10)=(-14)/(10) \approx -1.4`

Therefore, the x-interecepts are 5.6 and -1.4, approximately.