hamburger menu
All Coursesall course arrow
adda247
reward-icon
adda247
    arrow
    arrow
    arrow
    The roots of 22x−10×2x+16=02^{2x}-10×2^x+16=022x−10×2x+16=0​ are:
    Question

    The roots of 22x10×2x+16=02^{2x}-10×2^x+16=0​ are:

    A.

    2, 3

    B.

    1, 8

    C.

    2, 8

    D.

    1, 3

    Correct option is D

    Given:

    22x10×2x+16=02^{2x} - 10 \times 2^x + 16 = 0

    Solution:

    Let y=2xy = 2^x​, so 22x=y22^{2x} = y^2​​

    Rewritten Equation:

    y210y+16=0y^2 - 10y + 16 = 0​​

    Solve quadratic equation using factorization:

    y210y+16=(y2)(y8)=0y^2 - 10y + 16 = (y - 2)(y - 8) = 0​​

    Roots: y=2 or y=8.y = 2 \, \text{or} \, y = 8.​​

    Since y = 2x

    2x=2 x=1, 2x=8 x=32^x = 2 \implies x = 1, \\ \ \\ 2^x = 8 \implies x = 3 ​​

    Free Tests

    Free
    Must Attempt

    CBT-1 Full Mock Test 1

    languageIcon English
    • pdpQsnIcon100 Questions
    • pdpsheetsIcon100 Marks
    • timerIcon90 Mins
    languageIcon English
    Free
    Must Attempt

    RRB NTPC UG Level PYP (Held on 7 Aug 2025 S1)

    languageIcon English
    • pdpQsnIcon100 Questions
    • pdpsheetsIcon100 Marks
    • timerIcon90 Mins
    languageIcon English
    Free
    Must Attempt

    RRB Group D Full Mock Test 1

    languageIcon English
    • pdpQsnIcon100 Questions
    • pdpsheetsIcon100 Marks
    • timerIcon90 Mins
    languageIcon English
    test-prime-package

    Access ‘RRB Group D’ Mock Tests with

    • 60000+ Mocks and Previous Year Papers
    • Unlimited Re-Attempts
    • Personalised Report Card
    • 500% Refund on Final Selection
    • Largest Community
    students-icon
    390k+ students have already unlocked exclusive benefits with Test Prime!
    Our Plans
    Monthsup-arrow