Loading....
Coupon Accepted Successfully!

 

General Trinomials

 

The expression
x2 + (a + b)x + ab tells us that we need two numbers whose product is the last term and whose sum is the coefficient of the middle term. Consider the trinomial x2 + 5x + 6.  Now, two factors of 6 are 1 and 6, but 1 + 6 ≠ 5. However, 2 and 3 are also factors of 6, and 2 + 3 = 5. Hence, x2 + 5x + 6 = (x + 2)(x + 3).

 

Example
x2 – 7x – 18 = 0
Column A Column B
x 7

Which column is greater?

A. Column A
B. Column B
C. Both are Equal
D. Cannot be Determined

 

Now, both 2 and –9 are factors of 18, and 2 + (–9) = –7.

 

Hence, x2 – 7x – 18 = (x + 2)(x – 9) = 0. Setting each factor equal to zero yields x + 2 = 0 and x – 9 = 0.

 

Solving these equations yields x = –2 and 9. If x = –2, then Column B is larger.

 

However, if x = 9, then Column A is larger.

 

This is a double case, and the answer is (D).
 





Test Your Skills Now!
Take a Quiz now
Reviewer Name