The answer is a = 3/4 = 0.75
First get rid of the paranthesis,
![{a}^(2) (64 {a}^(2) - 3) = 64 {a}^(4) - 3 {a}^(2)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/pbpz83xo4a6una7eu6j739yog2ukgwchzd.png)
Then set the denominators equal:
![\frac{ 256 {a}^(4) - 12 {a}^(2)}{12} = \frac{81 - 12 {a}^(2) }{12}](https://img.qammunity.org/2019/formulas/mathematics/middle-school/sxgmhnom572mlrlvtbadeywn27v6m41m4n.png)
Then remove the denominators and solve:
![256 {a}^(4) - 12 {a}^(2) = 81 - 12 {a}^(2)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/em4jmmriihxngj2vu08ix67zrypkfhsyz1.png)
Eliminate -12a^2 by adding 12a^2 to both sides:
![256 {a}^(4) = 81](https://img.qammunity.org/2019/formulas/mathematics/middle-school/9jpnpov6a6r8ogqbg9sdudqt2hu94tr08p.png)
Take the fourth root of them or take the square root twice:
![\sqrt[4]{256 {a}^(4) } = \sqrt[4]{81} \\ 4a = 3](https://img.qammunity.org/2019/formulas/mathematics/middle-school/7bz23uwqtt1voivv09zam95rqwvb5bk1ti.png)
Divide both sides by 4:
![a = (3)/(4) = 0.75](https://img.qammunity.org/2019/formulas/mathematics/middle-school/xpbw2buz514cp4g4udgrlpm9yn2opboe9b.png)