m = 5 and n = 3
let f(x) = 2x³ - mx² + nx - 2 , then
f( - 1 ) = - 2 - m - n - 2 = - 12
f(2 ) = 16 - 4m + 2n - 2 = 0
Tidying up the 2 equations
- m - n = - 8 → (1)
- 4m + 2n = - 14 → ( 2)
multiply equation ( 1) by 2
- 2m - 2n = - 16 → ( 3 )
add ( 2 ) and ( 3 ) term by term
-6m = - 30 ⇒ m = 5 ( substitute m = 5 into (2 )
- 20 + 2n = - 14
2n = 6 ⇒ n = 3
Answer:
C
Step-by-step explanation:
A system of equations has infinitely many solutions when the two lines representing the equations coincide. i.e. the two equations are the same or a multiple of each other.
2y - 4x = 6
2y = 4x + 6
2y = 2(2x + 3)
y = 2x + 3
-y = -(2x + 3)
-y = -2x - 3
Hence the other equation is -y = -2x - 3
