Question

please find the value of t=?? for 2t - 0.7t^2 + 98= 0​

Answer 1

Step-by-step explanation:

WE WILL JUST FACTORISE THIS EQUATION....

--> 2t - 0.7t^2 + 98 = 0

NOW MULTIPLYING BOTH SIDES BY MINUS ( - )

--> - ( 2t - 0.7t^2 + 98 ) = - ( 0 )

--> -2t + 0.7t^2 - 98 = 0

--> 0.7t^2 - 2t - 98 = 0

AGAIN MULTIPLYING BOTH SIDES BY 10

--> 10 ( 0.7t^2 - 2t - 98 ) = 10 ( 0 )

--> 7t^2 - 20t - 980 = 0 -------Equation(1)

NOW , BY APPLYING QUADRATIC FORMULA THAT IS :

X = -b + √b^2 - 4ac / 2a

HERE IN EQUATION ( 1 )

b = - 20

c = -980

a = 7

--> ON PUTTING THESE VALUES IN QUADRATIC FORMULA

--> t = -(-20 ) + √ (-20) ^2 - 4 × 7× (-980) / 2×7

--> t = 20 + √ 400 - (- 27440) / 14

--> t = 20 + √ 400 + 27440 / 14

--> t = 20 + √ 27840 / 14

--> t = 20 + √ 27840 / 14

and

t = 20 - √27840 / 14

--> THERE ARE TWO VALUES OF ' t ' . SO WE WILL IGNORE THE NEGATIVE VALUE...

AND HENCE THE VALUE OF ' t ' is 20 + √27840 / 14 .

HOPE THIS HELPS !