Question

If -5 is a root of the equation 2x² + px – 15 = 0, then
(A) p = 3.
(B) p = 5.
(C) p = 7
(D) p = 1

Answer 1

Step-by-step explanation:

• $2( { - 5}^{2} ) + p( - 5) - 15 = 0 \\ \\ 2(25) - 5p - 15 = 0 \\ \\ 50 - 5p - 15 = 0 \\ \\ 50 - 15 = 5p \\ \\ 35 = 5p \\ \\ p = 35 \div 5 \\ \\ p = 7$