Question

One of the roots of equation 5m²+2m+k=0 is −7/5. Complete the following activity to find the value of ’k’.

Answer 1

GIVEN :
5m²+2m+k=0
Here, k is unknown. Since, m = -7/5 is one root of the equation,so it will satisfy the equation..

On Putting m = -7/5 in GIVEN equation,
5m²+2m+k=0
5(-7/5)² + 2(-7/5) + k = 0
5 × (49/25) -14/5 + k = 0
49/5 -14/5 + k = 0
35/5 + k = 0
k = -35/5= -7
k =  -7.
Hence,the value of k is -7.

HOPE THIS WILL HELP YOU...

Answer 2

here , GIVEN:- one of the roots of the quadratic equation 5m² + 2m + k = 0
where, one of the zeroes is m = -7/5

now let us put the value of m in the equation for finding the value of k.

5m² + 2m + k = 0

5(-7/5)² + 2(-7/5) + k = 0

5*(49)/25 - 14/5 + k = 0

49/5 - 14/5 + k = 0

(49 - 14)/5 + k = 0

35/5 + k = 0

k = -35/5 = -7

hence,the value of k = -7