Solve the Quadratic Equation: 2x² + x - 10 = 0

Question

Solve the following equation:

2x2+x10=0 2x^2+x-10=0

Video Solution

Solution Steps

00:00 Find X
00:04 Identify the coefficients
00:16 Use the roots formula
00:34 Substitute appropriate values according to the given data and solve
01:03 Calculate the square and products
01:17 Calculate the square root of 81
01:30 These are the 2 possible solutions (addition,subtraction)
01:47 And this is the solution to the question

Step-by-Step Solution

To solve the quadratic equation 2x2+x10=0 2x^2 + x - 10 = 0 , we'll apply the quadratic formula. The equation is in standard form ax2+bx+c=0 ax^2 + bx + c = 0 , where:

  • a=2 a = 2
  • b=1 b = 1
  • c=10 c = -10

Now, substitute these values into the quadratic formula:
x=b±b24ac2a x = \frac{{-b \pm \sqrt{{b^2 - 4ac}}}}{2a}

Step 1: Calculate the discriminant:

b24ac=124×2×(10)=1+80=81 b^2 - 4ac = 1^2 - 4 \times 2 \times (-10) = 1 + 80 = 81

Step 2: Take the square root of the discriminant:

81=9 \sqrt{81} = 9

Step 3: Solve for x x using the quadratic formula:

  • x1=1+94=84=2 x_1 = \frac{{-1 + 9}}{4} = \frac{8}{4} = 2
  • x2=194=104=52=212 x_2 = \frac{{-1 - 9}}{4} = \frac{-10}{4} = -\frac{5}{2} = -2\frac{1}{2}

The solutions to the equation 2x2+x10=0 2x^2 + x - 10 = 0 are x1=2 x_1 = 2 and x2=212 x_2 = -2\frac{1}{2} .

Therefore, the correct choice from the provided options is

x1=212,x2=2 x_1=-2\frac{1}{2}, x_2=2

Answer

x1=212,x2=2 x_1=-2\frac{1}{2},x_2=2