PERFECT SQUARES B2

If zx² - 20x + 25 = 0 is a perfect square, find the value of z .

Solution

In zx² - 20x + 25 = 0;   a=z, b=(-20) and c=25.

For the perfect square, b² = 4ac

(-20)² = 4 x z x 25

400 = 100z

400 =   100z

100      100

4 = z

Hence the value of z is 4

TRY THIS…………

If zx² - 24x + 4 = 0 is a perfect square, find the value of z .