How do you solve #n^{2} = 13n - 42#?
3 Answers
Explanation:
By Sum & Product
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Hope this helps!
rewrite the equation in the
Explanation:
The C term is positive so both binomial factors must be the same
The B terms is negative so both binomial factors must be negative
The sum of the binomial must equal 13 so find factors of 42
42 x 1
21 x 2
14 x 3
7 x 6
7 and 6 add to 13 so ( 7 and 6) are the correct set of factors.
Solving for each binomial gives the answers.
6 and 7
Explanation:
The 2 real roots have same positive sign (ac > 0, and ab < 0).
Find 2 real roots, both positive, knowing their sum (-b = 13), and their product (c = 42). They are 6 and 7.
Note . This method is simple and fast. It avoids doing factoring by grouping and solving the 2 binomials.