solve the following quadratic equations by using formula method x² - 3x - 2 = 0
Answers
Answer:
=
−
±
2
−
4
√
2
x=\frac{-{\color{#e8710a}{b}} \pm \sqrt{{\color{#e8710a}{b}}^{2}-4{\color{#c92786}{a}}{\color{#129eaf}{c}}}}{2{\color{#c92786}{a}}}
x=2a−b±b2−4ac
Once in standard form, identify a, b and c from the original equation and plug them into the quadratic formula.
2
−
3
−
2
=
0
x^{2}-3x-2=0
x2−3x−2=0
=
1
a={\color{#c92786}{1}}
a=1
=
−
3
b={\color{#e8710a}{-3}}
b=−3
=
−
2
c={\color{#129eaf}{-2}}
c=−2
=
−
(
−
3
)
±
(
−
3
)
2
−
4
⋅
1
(
−
2
)
√
2
⋅
1
x=\frac{-({\color{#e8710a}{-3}}) \pm \sqrt{({\color{#e8710a}{-3}})^{2}-4 \cdot {\color{#c92786}{1}}({\color{#129eaf}{-2}})}}{2 \cdot {\color{#c92786}{1}}}
x=2⋅1−(−3)±(−3)2−4⋅1(−2)
2
Simplify
Evaluate the exponent
Multiply the numbers
Add the numbers
Multiply the numbers
=
3
±
1
7
√
2
x=\frac{3 \pm \sqrt{17}}{2}
x=23±17
3
Separate the equations
4
Solve
Solution
=
3
±
1
7
√
2