Quadratic Equations
Advertisement
Zigya App

Check whether the following are quadratic equations:
(x – 3) (2x + 1) = x(x + 5)

L.H.S. = (x – 1) (2x + 1)
= 2x2 + x – 2x – 1
= 2x2 – x – 1
R.H.S. = x(x + 5) = x2 + 5x
∴ 2x2 – x – 1 = x2 + 5x
⇒ 2x2 – x2 – x – 5x – 1 = 0
⇒ x2 – 6x – 1 = 0
∵ It is of the form ax2 + bx + c = 0 where a = 1, b = –b, c = –1.
Hence, the given equation is a quadratic equation.

542 Views
  • Switch
    • Advertisement
    Check whether the following are quadratic equations:
    (x + 1)2 = 2(x – 3)
    Answer
    Check whether the following are quadratic equations:
    x2 – 2x = (–2) (3 – x)
    Answer
    Check whether the following are quadratic equations:
    (x – 2) (x + 1) = (x – 1) (x + 3)
    Answer
    Check whether the following are quadratic equations:
    (2x –1) (x–3) = (x + 5)(x–1)
    Answer
    First 1 2 3 Last
    Advertisement