Question

(x+4),(x+12),(x-1) and (x+5) are in proportion .find the value of x​

Answer 1

Answer:

x = 16

Step-by-step explanation:

(x +4) : (x +12) ::  (x-1)(x +5)

As they are in proportion,

Product of means = Product of extremes

(x + 4)* (x +5) = (x + 12)(x - 1)   {Use FOIL method}

x*x +x*5 +4*x + 4*5 = x *x + x*(-1) +12*x + 12*(-1)

x² + 5x + 4x + 20 = x² - x +12x - 12            {Now combine like terms}

 x² + 9x + 20  = x² + 11x -12

x² + 9x +20 - x² - 11x = -12

x² - x² + 9x - 11x     = -12 - 20          

    0   - 2x              = - 32

                       -2x = -32          {Divide both sides by -2}

                           x = -32/-2

                          x = 16