209k views
0 votes
What number should be added to the expression x2 + 14x to change it into a perfect square trinomial?

(Points : 1)
7
14
28
49

User Angeles
by
7.9k points

2 Answers

3 votes
# to be added to x² +14x to change it to a perfect square trinomial is
(14/2)² = 7²
= 49
the trinomial is x² + 14x + 49 = (x +7)²
User James Riordan
by
7.8k points
7 votes

(x+a)^2=x^2+2\cdot x\cdot a+a^2\ \ \ \Rightarrow \ \ \ \ 2\cdot x\cdot a=14x\ \ \ \Leftrightarrow\ \ \ 2a=14\ /:2\\\\a=7\ \ \ \Rightarrow\ \ \ a^2=7^2=49\\\\\ \ \ \Rightarrow\ \ \ a\ perfect\ square\ trinomial=(x+7)^2
User Umang Mathur
by
8.5k 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