How do you factor the expression #k^2 + 11k + 28#?

Question

2231 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-03-16T18:39:14

#(k+4)(k+7)#

#"Consider the factors of 28 which sum to + 11"#

#"the factors of + 28 which sum to + 11 are + 7 and + 4"#

#rArrk^2+11k+28=(k+4)(k+7)#

Answer 2 · 2018-03-16T18:43:59

#(k+7)(k+4)#

Start by looking at your first term: #k^2#

Now look at the signs of the second two terms: both are positive
From these observations, we know our factors will be:
(k+___)(k+_)

because k times k will get us #k^2# , and both factors having a "+" sign means that our second and third terms will both be positive.

Now, what two numbers will equal 11 when added together, and 28 when multiplied together?
The two numbers are 7 and 4.

7+4=11
7*4=28

So these complete our factors, #k+7# and #k+4#