Solve the Quadratic Equation: 3x² + 10x - 8 = 0

Question

Solve the following equation:

3x2+10x8=0 3x^2+10x-8=0

Video Solution

Solution Steps

00:00 Find X
00:04 Identify the coefficients
00:14 Use the roots formula
00:35 Substitute appropriate values according to the given data and solve
00:59 Calculate the square and products
01:16 Calculate the square root of 196
01:33 These are the 2 possible solutions (addition,subtraction)
01:48 And this is the solution to the question

Step-by-Step Solution

To solve the quadratic equation 3x2+10x8=0 3x^2 + 10x - 8 = 0 , we will apply the quadratic formula.

First, identify the coefficients:
a=3 a = 3 , b=10 b = 10 , c=8 c = -8 .

Calculate the discriminant Δ \Delta :
Δ=b24ac=1024×3×(8)=100+96=196 \Delta = b^2 - 4ac = 10^2 - 4 \times 3 \times (-8) = 100 + 96 = 196

Since the discriminant Δ=196 \Delta = 196 is greater than zero, the quadratic equation has two distinct real roots.

Now apply the quadratic formula:
x=b±Δ2a=10±1966 x = \frac{-b \pm \sqrt{\Delta}}{2a} = \frac{-10 \pm \sqrt{196}}{6}

Calculate the roots:

  • Root x1 x_1 :
    x1=10+146=46=23 x_1 = \frac{-10 + 14}{6} = \frac{4}{6} = \frac{2}{3}
  • Root x2 x_2 :
    x2=10146=246=4 x_2 = \frac{-10 - 14}{6} = \frac{-24}{6} = -4

Thus, the solutions are x1=23 x_1 = \frac{2}{3} and x2=4 x_2 = -4 .

Therefore, the solution to the equation 3x2+10x8=0 3x^2 + 10x - 8 = 0 is x1=23,x2=4 x_1 = \frac{2}{3}, x_2 = -4 .

Answer

x1=23,x2=4 x_1=\frac{2}{3},x_2=-4