Solve the Polynomial Equation: 3x³ - 10x² + 7x = 0 for X

Question

3x310x2+7x=0 3x^3-10x^2+7x=0

Video Solution

Solution Steps

00:00 Find X
00:04 Break down X³ into factors X² and X
00:09 Break down X² into factors X and X
00:15 Find the common factor
00:22 Take out the common factor from the parentheses
00:33 Find what makes each factor zero in the product, so it equals 0
00:36 This is one solution
00:40 Now let's find the solutions that make the parentheses zero
00:48 Break down 10 into 3 and 7
00:54 Take out common factors outside the parentheses
01:00 Find the common factor
01:08 Find what makes each factor zero in the product, so it equals 0
01:12 This is the second solution
01:15 Isolate X
01:24 And this is the solution to the question

Step-by-Step Solution

To solve the problem 3x310x2+7x=0 3x^3 - 10x^2 + 7x = 0 , follow these steps:

  • Step 1: Factor out the greatest common factor (GCF). The common factor in all terms is x x . Factoring out x x gives:

x(3x210x+7)=0 x(3x^2 - 10x + 7) = 0

  • Step 2: Apply the Zero Product Property. Set each factor equal to zero:

x=0 x = 0 or 3x210x+7=0 3x^2 - 10x + 7 = 0

  • Step 3: Solve the quadratic equation 3x210x+7=0 3x^2 - 10x + 7 = 0 using the quadratic formula:

The quadratic formula is x=b±b24ac2a x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} . Here, a=3 a = 3 , b=10 b = -10 , c=7 c = 7 .

Calculate the discriminant:

b24ac=(10)24(3)(7)=10084=16 b^2 - 4ac = (-10)^2 - 4(3)(7) = 100 - 84 = 16

Since the discriminant is a perfect square, this quadratic has rational roots. Using the quadratic formula gives:

x=(10)±166=10±46 x = \frac{-(-10) \pm \sqrt{16}}{6} = \frac{10 \pm 4}{6}

Thus, the solutions are:

x=10+46=146=73 x = \frac{10 + 4}{6} = \frac{14}{6} = \frac{7}{3}

x=1046=66=1 x = \frac{10 - 4}{6} = \frac{6}{6} = 1

  • Step 4: Combine all solutions. The solutions to the original equation are:

x=0 x = 0 , x=1 x = 1 , and x=73 x = \frac{7}{3} .

Therefore, the solution to the problem is x=0,1,73 x = 0, 1, \frac{7}{3} .

Answer

x=0,1,73 x=0,1,\frac{7}{3}