Tewtor Logo

Tewtor.ai

AI Solution

Powered by Tewtor.ai

Shared by Mohammed Usama0 views

QProblem

why did you divide by 2 first?

ASolution

Dividing by 2 (the greatest common factor) is not required to solve the equation, but it makes the algebra much easier and reduces the chance of mistakes. Here’s why:

  1. Simplifies the coefficients
    The original quadratic is

    2x28x+6=0.2x^{2} - 8x + 6 = 0 .

    All three terms share a factor of 2. If we factor that 2 out of the left‑hand side we get

    2(x24x+3)=0.2\bigl(x^{2} - 4x + 3\bigr) = 0 .

    Because the factor 2 is never zero, the equation is equivalent to

    x24x+3=0.x^{2} - 4x + 3 = 0 .

    Now the leading coefficient is 1, so the constant term and the linear coefficient are small integers (3 and –4). That makes the next step—finding two numbers that multiply to 3 and add to –4—straightforward.

  2. Reduces arithmetic errors
    If we tried to factor the original form directly, we would need two numbers whose product is 2×6=122 \times 6 = 12 (the product of the leading coefficient and the constant) and whose sum is 8-8. The possible pairs (±1, ±12), (±2, ±6), (±3, ±4) are more numerous, and it’s easy to pick the wrong sign or pair. After dividing by 2, the product we need is just +3, and the only integer pair that works is 1-1 and 3-3.

  3. Keeps the equation equivalent
    Dividing every term (or factoring out the GCF) does not change the set of solutions because we are multiplying the entire left side by a non‑zero constant. The equation

    2x28x+6=02x^{2} - 8x + 6 = 0

    has exactly the same solutions as

    x24x+3=0.x^{2} - 4x + 3 = 0 .

    (If we divided only one term, the equation would no longer be equivalent and we would get the wrong answer—that’s a common mistake.)

  4. Makes the zero‑product step clearer
    After the simplification we can factor directly:

    x24x+3=(x1)(x3)=0,x^{2} - 4x + 3 = (x-1)(x-3) = 0 ,

    leading immediately to x=1x = 1 or x=3x = 3. If we kept the factor 2 outside, we would have

    2(x1)(x3)=0,2(x-1)(x-3) = 0 ,

    and we would still set each factor (x1)(x-1) and (x3)(x-3) to zero, but the extra “2” is unnecessary work.


Bottom line:
Dividing by the GCF (or factoring it out) is a convenient algebraic shortcut that leaves the same solutions while giving you smaller, easier‑to‑handle numbers. Just remember to apply the division to every term; otherwise the equation changes and you’ll get incorrect results.

Shared on 8/2/2026

Need help with your own problems?

Get instant AI tutoring and step-by-step solutions on Tewtor.ai

© 2024 Tewtor.ai - AI-Powered Learning Platform