Answer:
or, m = - 3
Explanation:
The quadratic formula is given in this problem as
2m² - m - 21 = 0
Now, we can solve this equation and find the values of m for which the above equation is satisfied.
Now, 2m² - m - 21 = 0 {Factorize the left hand side expression}
⇒ 2m² - 7m + 6m - 21 = 0
⇒ m ( 2m - 7 ) + 3 ( 2m - 7 ) = 0
⇒ ( 2m - 7 )( m + 3 ) = 0
⇒
or, m = - 3 (Answer)