Question

solve the following 4x²-25=0​

Answer 1

Solution :

$\: \: \: \: \: \: \: {4x}^{2} - 25 = 0$

$= > (2x) ^{2} - {5}^{2} = 0$

$= > (2x - 5)(2x + 5) = 0$

$= > 2x - 5 = 0 \: \: \: \: or \: \: \: \: 2x + 5 = 0$

$= > 2x = 5 \: \: \: \: or \: \: \: \: 2x = - 5$

$= > x = \frac{5}{2} \: \: \: \: or \: \: \: \: x = \frac{ - 5}{2} .$

Answer 2

Answer:

Use the 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}}}

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.

4

2

−

2

5

=

0

4x^{2}-25=0

4x2−25=0

=

4

a={\color{#c92786}{4}}

a=4

=

0

b={\color{#e8710a}{0}}

b=0

=

−

2

5

c={\color{#129eaf}{-25}}

c=−25

=

−

0

±

0

2

−

4

⋅

4 of

(

−

2

5

)

√

2

⋅

4