51.4k views
3 votes
What value of b makes the expression x^2 + bx + 4 a perfect square?
1
0
2
4

User Mbwasi
by
8.1k points

2 Answers

4 votes

Answer:

4

Explanation:

The constant term 4 is obtained by

adding (half the coefficient of the x- term)²

4 = 2²

Then b = 4

x² + 4x + 4 = (x + 2)² ← a perfect square

User Skydoor
by
8.6k points
5 votes

Answer:

b=4 makes the equation a perfect square.

Explanation:

As long as you factorize out the equation, you'll get a result of (x+2)^2. This multiplied using foil gives you, x^2 + 2x + 4. Making it a perfect square. You could also have -2 = b which makes a perfect square, but that's not in the options.

User Season
by
7.8k points

No related questions found

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