204k views
4 votes
Can you help me factor the expression x^2+4x-21

User Macho
by
8.0k points

1 Answer

3 votes

To factor this expression we need to find two numbers which sum is 4 and the product is -21.

Now, 21 has only 2 factors (besides 1 and 21), 7 and 3, se we need to write them in a way such that they sum 4, so


x^2+4x-21=(x+7)(x-3)

we see that 7-3=4 and 7(-3)=-21, so the factorization is correct.

User Ajmartin
by
8.4k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories