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5 votes
Find the values of a and b such that

x^2 + 3x + 4 = (x + a)^2 + b


URGENT!

*silly answers will be reported

User JFM
by
5.3k points

1 Answer

6 votes

Answer:

a = 1.5

b = 1.75

Explanation:

First, we need to solve
(x+a)^2 and replace the result in the initial equation as:


x^2+3x+4=(x+a)^2+b\\x^2+3x+4=x^2+2ax+a^2+b

Then, this equality apply only if the coefficient of
x is equal in both sides and the constant is equal in both sides.

It means that we have two equations:


3x=2ax\\4=a^2+b

So, using the first equation and solving for a, we get:


3x=2ax\\3=2a\\a=(3)/(2)=1.5

Finally, replacing the value of a in the second equation and solving for b, we get:


4=a^2+b\\4=1.5^2+b\\b=4-1.5^2\\b=4-2.25\\b=1.75

User Ymerej
by
5.4k points