Identify Common Factor: Identify the common factor in the polynomial.The polynomial r8−5r4u3−14u6 has a common factor of r4 in the first two terms, but not in the third term. However, we can look for a different type of factorization, which is factoring by grouping or looking for a pattern that resembles a known factorable form.
Recognize Quadratic Form: Recognize the polynomial as a quadratic in form. The polynomial can be seen as a quadratic in terms of r4, where r4 is the variable and u3 is a constant. The polynomial then takes the form of (r4)2−5r4u3−14u6, which resembles a quadratic equationax2+bx+c.
Factor as Quadratic: Factor the polynomial as if it were a quadratic.We will use the factoring technique for quadratics to factor the polynomial. We need to find two numbers that multiply to give −14u6 (the constant term) and add to give −5u3 (the coefficient of the middle term). These two numbers are −7u3 and −2u3.
Write as Binomials: Write the polynomial as a product of two binomials.The polynomial can now be written as (r4−7u3)(r4+2u3). This is the factorization of the polynomial into two binomials.
Check Factorization: Check the factorization by expanding the binomials.To ensure that the factorization is correct, we can multiply the two binomials to see if we get the original polynomial:(r4−7u3)(r4+2u3)=r8+2r4u3−7r4u3−14u6=r8−5r4u3−14u6.The expanded form matches the original polynomial, confirming that the factorization is correct.
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