182k views
1 vote
Can someone please help me with the problem? I have the answer but I need the step by step explanation for it.

Directions: Solve the folowing equation.

-2x^2+4x=9

Answer: (2-i√-14)/2, (2+i√-14)/2



1 Answer

4 votes
Of course, I'd be happy to help you with the problem! Let's go through the steps to solve the equation -2x^2 + 4x = 9.

Step 1: Start by rearranging the equation to bring all the terms to one side, so we have a quadratic equation in standard form: -2x^2 + 4x - 9 = 0.

Step 2: To solve the quadratic equation, we can use the quadratic formula: x = (-b ± √(b^2 - 4ac)) / (2a). In this case, a = -2, b = 4, and c = -9.

Step 3: Substitute the values of a, b, and c into the quadratic formula and simplify:

x = (-4 ± √(4^2 - 4(-2)(-9))) / (2(-2))
x = (-4 ± √(16 - 72)) / (-4)
x = (-4 ± √(-56)) / (-4)

Step 4: Simplify the square root of -56. Since the square root of a negative number is not a real number, we can express it as i√56:

x = (-4 ± i√56) / (-4)

Step 5: Simplify the expression by dividing both the numerator and denominator by -4:

x = (4/4) ± (i√56/4)
x = 1 ± (i√14)

So, the solutions to the equation -2x^2 + 4x = 9 are (2 - i√14)/2 and (2 + i√14)/2.

I hope this step-by-step explanation helps! Let me know if you have any other questions.
User Natecat
by
8.2k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories