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Choose the best answer from the four choices given. You may use scratch

paper.
Which of the following equations has both 1 and -3 as solutions?
O x2 - 2x -3 =0
x² + 2X-3 =0
O x2 - 4x +3 =0
O x2 + 4x +3 =0

User Oleviolin
by
6.5k points

1 Answer

3 votes

Answer:

The answer is B.

Explanation:

Instead of solving each equation, simply think about it alternatively.

Recall that quadratic equations can also be written as:
(x-a)(x-b), where
a and
b are the solutions.

We know that 1 and -3 are solutions, so we can substitute them in for
a and
b.

Thus, we have:


(x-(1))(x-(-3))


(x-1)(x+3)

Now, expand:


x^2+3x-x-3


x^2+2x-3

The answer is B.

User Gabriel Vasile
by
5.5k points