Question

Of the following, which is the solution to 2x2 + 3x = −5? (6 points) Select one: a. the quantity negative three plus or minus i times the square root of thirty one over four b. the quantity negative three plus or minus i times the square root of thirty one over two c. the quantity three plus or minus i times the square root of thirty one over four d. the quantity negative three plus or minus i times the square root of fifty over four

Answer 1

"2x2 + 3x = −5" should be re-written as 2x^2 + 3x +5 = 0. This is a quadratic equation with a=2, b=3 and c=5. Thus, the roots are:

-3 plus or minus √(9-4[2][5])

x = ---------------------------------------------

4

or:

-3 plus or minus √(-31)

x = ----------------------------------

4

or:

-3 plus or minus i*√31

x = ----------------------------------

4