Question

There are two number 'x' making the value of the `|(1, -2, 5),(2, x, -1),(0, 4, 2x)|` equals to 86. The sum of there two number, is:

Options

• – 4

• 5

• – 3

• 9

Answer 1

– 4

Explanation:

D = `(2x^2 + 4) - 2(- 4x - 20)`

`2x^2 + 8x + 44` = 86

`2x^2 + 8x - 42` = 0

⇒ `x^2 + 4x - 21` = 0

⇒ `a + beta` = 4