Question

Solve quadratic equation :
4(7x-1/x)2-8(7x-1/x)+3=0

Answer 1

Given: The equation 4(7x-1/x)² - 8(7x-1/x) + 3 = 0

To find: Solve the quadratic equation.

Solution:

• Now we have given the equation:

                 4(7x-1/x)² - 8(7x-1/x) + 3 = 0

• Let 7x-1/x = y, then:

                 4y² - 8y + 3 = 0

                 4y²- 6y - 2y + 3  = 0

                  2y(2y-3) - 1(2y-3)  = 0

                  (2y-1)(2y-3) = 0

                  y = 1/2,3/2

• Re substituting again, we get:

                 7x-1/x = 1/2     or 7x-1/x = 3/2

                 2(7x-1) = x       or 2(7x-1) = 3x

                 14x - 2 = x       or 14x - 2 = 3x

                 13x = 2            or 11x = 2

                 x = 2/13           or x = 2/11

Answer:

                 So the value of x is 2/13 or 2/11.