What is the quadratic formula for this problem

or, m = - 3

Step-by-step 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)

lockers 1, 4, 9, 16, 25, 40, and 49 are open

i ran through it by the other answer is wrong