How would you factorise the equation 4n squared add 11n subtract 3?

Answer 1

4n2 + 11n - 3

The following method is mathematically correct but may not be taught in school so be careful about using it.

Multiply the last term by the coefficient of the first term:

4n2 + 11n - 12

Reduce the power of n in the first term by one and write them as the first terms in two binomial expressions:

(4n )*(4n ).

Find 2 factors of the last term (12), and since it is negative, the difference between these two factors should be the middle term (1 and 12). The larger of these takes the same sign as the middle term (so +12) and the other takes the opposite sign (-1).

Write these as the second terms in the binomial expressions.

(4n +12)*(4n - 1).

Finally, divide out the 4 from the first bracket [this is to offset the earlier multiplication by 4] to give the answer:

(n + 3)*(4n - 1)