Question

solve the following quadratic equation by factorisation x2+2x-5=0​

Answer 1

$x {}^{2} + 2x - 5 = 0$

a = 1

b = 2

c = −5

$x = \frac{ - 2± \sqrt{2 {}^{2} - 4 \times 1( - 5) } }{2 \times 1}$

x = -1 ± √6

Answer 2

Answer:

quadratic formula

=

−

±

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}}}

Once in standard form, identify a, b and c from the original equation and plug them into the quadratic formula.

2

+

2

−

5

=

0

x^{2}+2x-5=0

=

1

a={\color{#c92786}{1}}

=

2

b={\color{#e8710a}{2}}

=

−

5

c={\color{#129eaf}{-5}}

=

−

2

±

2

2

−

4

⋅

1

(

−

5

)