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a^{2}=4\left(\frac{a}{2}+2\right)^{2}-4\times 8^{2}
Multiply both sides of the equation by 4.
a^{2}=4\left(\left(\frac{a}{2}\right)^{2}+4\times \frac{a}{2}+4\right)-4\times 8^{2}
Use binomial theorem \left(a+b\right)^{2}=a^{2}+2ab+b^{2} to expand \left(\frac{a}{2}+2\right)^{2}.
a^{2}=4\left(\frac{a^{2}}{2^{2}}+4\times \frac{a}{2}+4\right)-4\times 8^{2}
To raise \frac{a}{2} to a power, raise both numerator and denominator to the power and then divide.
a^{2}=4\left(\frac{a^{2}}{2^{2}}+2a+4\right)-4\times 8^{2}
Cancel out 2, the greatest common factor in 4 and 2.
a^{2}=4\left(\frac{a^{2}}{2^{2}}+\frac{\left(2a+4\right)\times 2^{2}}{2^{2}}\right)-4\times 8^{2}
To add or subtract expressions, expand them to make their denominators the same. Multiply 2a+4 times \frac{2^{2}}{2^{2}}.
a^{2}=4\times \frac{a^{2}+\left(2a+4\right)\times 2^{2}}{2^{2}}-4\times 8^{2}
Since \frac{a^{2}}{2^{2}} and \frac{\left(2a+4\right)\times 2^{2}}{2^{2}} have the same denominator, add them by adding their numerators.
a^{2}=4\times \frac{a^{2}+8a+16}{2^{2}}-4\times 8^{2}
Do the multiplications in a^{2}+\left(2a+4\right)\times 2^{2}.
a^{2}=\frac{4\left(a^{2}+8a+16\right)}{2^{2}}-4\times 8^{2}
Express 4\times \frac{a^{2}+8a+16}{2^{2}} as a single fraction.
a^{2}=\frac{4\left(a^{2}+8a+16\right)}{2^{2}}-4\times 64
Calculate 8 to the power of 2 and get 64.
a^{2}=\frac{4\left(a^{2}+8a+16\right)}{2^{2}}-256
Multiply 4 and 64 to get 256.
a^{2}=\frac{4\left(a^{2}+8a+16\right)}{2^{2}}-\frac{256\times 2^{2}}{2^{2}}
To add or subtract expressions, expand them to make their denominators the same. Multiply 256 times \frac{2^{2}}{2^{2}}.
a^{2}=\frac{4\left(a^{2}+8a+16\right)-256\times 2^{2}}{2^{2}}
Since \frac{4\left(a^{2}+8a+16\right)}{2^{2}} and \frac{256\times 2^{2}}{2^{2}} have the same denominator, subtract them by subtracting their numerators.
a^{2}=\frac{4a^{2}+32a+64-1024}{2^{2}}
Do the multiplications in 4\left(a^{2}+8a+16\right)-256\times 2^{2}.
a^{2}=\frac{4a^{2}+32a-960}{2^{2}}
Combine like terms in 4a^{2}+32a+64-1024.
a^{2}=\frac{4a^{2}+32a-960}{4}
Calculate 2 to the power of 2 and get 4.
a^{2}=-240+8a+a^{2}
Divide each term of 4a^{2}+32a-960 by 4 to get -240+8a+a^{2}.
a^{2}-8a=-240+a^{2}
Subtract 8a from both sides.
a^{2}-8a-a^{2}=-240
Subtract a^{2} from both sides.
-8a=-240
Combine a^{2} and -a^{2} to get 0.
a=\frac{-240}{-8}
Divide both sides by -8.
a=30
Divide -240 by -8 to get 30.