Factorise: $a^{4} - 20 a^{2} + 64$

(a + 2) (a - 2) (a + 4) (a - 4)

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

{(a - 2)}^{2} {(a - 4)}^{2}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

{(a - 2)}^{2} {(a + 4)}^{2}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

None of these

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is A $(a + 2) (a - 2) (a + 4) (a - 4)$
$a^{4} - 20 a^{2} + 64$
$= a^{4} - 16 a^{2} - 4 a^{2} + 64$
$= a^{2} (a^{2} - 16) - 4 (a^{2} - 16)$
$= (a^{2} - 16) (a^{2} - 4)$
$= (a + 4) (a - 4) (a + 2) (a - 2)$

Suggest Corrections

Similar questions

Factorise $a^{2} + \frac{1}{a^{2}} + 2 - 7 a - \frac{7}{a}$

\frac{a^{2} - 4 a + 4}{- a^{2} + 2 a + 15} \times \frac{a^{2} - 9}{(a - 2)^{2}}

Factorise :

(a + b)³ - 8

My attempt

= (a + b)³- (2)³

= (a + b - 2) {(a + b)²+ (2)² + 2(a + b)}

What should I do not?

(a^{2}) (2 a^{22}) (4 a^{26})

Factorise $8 - 2 (a - b)^{2}$

Join BYJU'S Learning Program