Math, asked by jharna, 1 year ago

if x=-2 a solution of the quadratic equation x2-2x 8=0

yasummu: x^2 - 2x +8 or -8?

Answers

Answered by assingh

yes it is true -4-4+8 = 0

assingh: sorry...

jharna: thanks

yasummu: you are most welcome

yasummu: In the question above are we asked to find another root of the equation?

yasummu: Or else your question is ``Is x = -2 a solution of it?``

jharna: if one root of the qe x^2-11x+k=0 is 9 find the value of k

jharna: this is d given question

yasummu: yes i understood this but the above actual question

jharna: hmmm thnx

jharna: yasummu actually i m private candidate so i need more answer for more questions

Answered by yasummu

Question : Is x=-2, a solution of the quadratic equation x² - 2x +8 = 0
⇒(-2)² - 2(-2) + 8 = 0
⇒ 4 - (-4) + 8 = 0
⇒4+4 + 8 = 0
⇒16 is not equal to 0
Therefore it is not a root of the given eq

If the given eq is x² - 2x - 8 then the solution is
x = -2
⇒(-2)² - 2(-2) - 8 = 0
⇒4- (-4) - 8 = 0
⇒4+4 - 8 = 0
⇒8 - 8 = 0
⇒0=0
Therefore -2 is a root of the given eq

jharna: thank u

jharna: construct the QE whose roots are 5,-4

yasummu: Roots are 5, -4

jharna: yeah

yasummu: This means that x= 5, x= -4 ; the factors are (x-5) and (x+4) Therefore the Q.E = (x-5)(x+4)=0 ; x^2 + 4x - 5x - 20; x^2 - x - 20. Therefor ethe Q.E = x^2 - x - 20

jharna: seriously u r awesome dear u r helping me thank u so so much

yasummu: if you understand it very well then thank you , and welcome

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