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Using the quadratic formula to solve 2
4x - 7. what are the values of x2

1 Answer

4 votes

Answer:

x=
-2\pm √(11)

Explanation:

Here is the correct question: Using the quadratic formula to solve

x²+4x - 7. what are the values of x.

Solving by using quadratic formula.

Formula:
\frac{-b\pm \sqrt{b^(2)-4(ac) } }{2a}

∴ In the expression
x^(2) +4x-7, we have a= 1, b= 4 and c= -7.

Now, subtituting the value in the formula.

=
\frac{-4\pm \sqrt{4^(2)-4(1* -7) } }{2* 1}

=
\frac{-4\pm \sqrt{4^(2)-4(-7) } }{2}

Opening parenthesis.

=
(-4\pm √(16+28 ) )/(2* 1)

=
(-4\pm √(44))/(2)

We know 2²=4

=
\frac{-4\pm \sqrt{2^(2)* 11 }}{2}

we know √a²=a

=
(-4\pm 2 √(11 ))/(2)

Taking 2 as common in the expression.

=
(2(-2\pm √(11)) )/(2)

Cancelling 2

=
-2\pm √(11)

Hence we get,
x=-2\pm√(11)

User Abbotto
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