-a^2(a^5÷a^3)+(-3a^2)^2+(2a^3)^2÷(-1/2a)^2+2a^4-(-a^2)^2
-a^2(a^5÷a^3)+(-3a^2)^2+(2a^3)^2÷(-1/2a)^2+2a^4-(-a^2)^2
-a^2(a^5÷a^3)+(-3a^2)^2+(2a^3)^2÷(-1/2a)^2+2a^4-(-a^2)^2
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$-a^2(a^5÷a^3)+(-3a^2)^2+(2a^3)^2÷\left(-\frac{1}{2}a\right)^2+2a^4-(-a^2)^2=$
$=-a^2(a^{5-3})+9a^{2×2}+4a^{3×2}÷\frac{1}{4}a^2+2a^4-a^{2×2}=$
$=-a^2×a^2+9a^4+4a^6÷\frac{1}{4}a^2+2a^4-a^4=$
$=-a^{2+2}+9a^4+(4×4)a^{6-2}+a^4=$
$=-a^4+9a^4+16a^4+a^4=$
$=(-1+9+16+1)a^4=$
$=25a^4$