1. 2x² – 6x + 3 = 0 The given equations is of the form ax² + bx + c = 0 in which a = 2, b = - 6, c = 3. Therefore, D = b² - 4ac = (-6)² - 4 × 2 × 3 = 36 - 24 12 > 0 So, the roots of quadratic equation are real and unequal. Hence, x = 6±√12/4 = 6±3√3/4 = 3±√3/2 [As x = -b±√b² - 4ac/2a] Either x = 3±√Read more

    2x² – 6x + 3 = 0
    The given equations is of the form ax² + bx + c = 0 in which a = 2, b = – 6, c = 3.
    Therefore, D = b² – 4ac = (-6)² – 4 × 2 × 3 = 36 – 24 12 > 0
    So, the roots of quadratic equation are real and unequal.
    Hence, x = 6±√12/4 = 6±3√3/4 = 3±√3/2 [As x = -b±√b² – 4ac/2a]
    Either x = 3±√3/2 or x = 3-√3/2
    Hence, the roots of the quadratic equation are 3+√3/2 and 3-√3/2.

    See less
    • 7
  2. Let the side of larger square = x m let the side of smaller square = y m According to question, x² + y² = 468 ...(i) Difference between parimeters, 4x - 4y = 24 ⇒ x - y = 6 ⇒ x = 6 + y ...(ii) Putting the value of x in equation (i), we get (y + 6)² + y² = 468 ⇒ y² + 12y + 36 + y² = 468 ⇒ 2y² + 12y -Read more

    Let the side of larger square = x m
    let the side of smaller square = y m
    According to question, x² + y² = 468 …(i)
    Difference between parimeters, 4x – 4y = 24
    ⇒ x – y = 6
    ⇒ x = 6 + y …(ii)
    Putting the value of x in equation (i), we get
    (y + 6)² + y² = 468
    ⇒ y² + 12y + 36 + y² = 468
    ⇒ 2y² + 12y – 432 = 0
    ⇒ y² + 6y – 216 = 0
    ⇒ y² + 18y – 12y – 216 = 0
    ⇒ y(y + 18) – 12(y + 18) = 0
    ⇒ (y + 18) (y – 12) = 0
    ⇒ (y + 18) = 0 or (y – 12) = 0
    Either y = – 18 or y = 12
    But, y ≠ – 18, as x is the side of square, which can’t be negative. So, y = 12
    Hence, the side of smaller square = 12 m
    Putting the value of y in equation (ii). we get
    side of large square = x = y + 6 = 12 + 6 = 18 m.

    See less
    • 1
  3. Let, the speed of passenger train = x Km/h Therefore, the speed of express train = x + 11 km/h Distance travelled = 132 Km Time taken by passenger tarin t₁ = 133/x hours [As, time = distance/speed] Time taken by express train t₂ = 132/x+11 hours According to question, 132/x = 132/x + 11 = 1 ⇒ 132/xRead more

    Let, the speed of passenger train = x Km/h
    Therefore, the speed of express train = x + 11 km/h
    Distance travelled = 132 Km
    Time taken by passenger tarin t₁ = 133/x hours [As, time = distance/speed]
    Time taken by express train t₂ = 132/x+11 hours
    According to question,
    132/x = 132/x + 11 = 1
    ⇒ 132/x = 132/x + 11 = 1
    ⇒ 132(x + 11) – 132x/x(x + 11) = 1
    ⇒ 132x + 1452 – 132x = x(x + 11)
    ⇒ 1452 = x² + 11x
    ⇒ x² + 11x – 1452 = 0
    ⇒ x² 44x – 33x – 1452 = 0
    ⇒ x(x + 44) – 33(x + 44) = 0
    ⇒ (x + 44) (x – 33) = 0
    ⇒ (x + 44) = 0 or (x – 33) = 0
    Either x = -44 or x = 33
    But x ≠ -44, as x is the speed of train, which can’t be negative. So, x = 33
    Hence, the speed of passenger train = 33Km/h
    The speed of express train = 33 + 11 = 44Km/h

    See less
    • 1
  4. Let, the speed of train = x km/h Distance = 360 km Therefore, the time taken t₁ = 360/x hours [Because time = distance/speed] If the speed had been 5 km/h more, than the t₂ = 360/x+5 hours According to question, 360/x = 360/x+5 + 1 ⇒ 360/x - 360/x + 5 = 1 ⇒ 360(x + 5) - 360x/x(x+5) = 1 ⇒ 360x + 1800Read more

    Let, the speed of train = x km/h
    Distance = 360 km
    Therefore, the time taken t₁ = 360/x hours [Because time = distance/speed]

    If the speed had been 5 km/h more, than the t₂ = 360/x+5 hours
    According to question,
    360/x = 360/x+5 + 1
    ⇒ 360/x – 360/x + 5 = 1
    ⇒ 360(x + 5) – 360x/x(x+5) = 1

    ⇒ 360x + 1800 – 360x = x(x+5)
    ⇒ 1800 = x² + 5x
    ⇒ x² + 5x – 1800 = 0
    ⇒ x² + 45x – 40x – 1800 = 0
    ⇒ x(x + 45) – 40(x + 45) = 0
    ⇒ (x + 45)(x – 40) = 0
    ⇒ (x + 45) = 0 or (x – 40) = 0
    Either x = – 45 or x = 40
    But, x ≠ – 45, as x is the speed of train which can not be nagative.
    So, x = 40
    Hence, the speed of train is 40Km/h.

    See less
    • 1