1.(-2x的2次方)的三次方-(-x的三次方)的二次方

1.
(-2x²)³-(-x³)²
=-8x^6-x^6
=-9x^6
2
（-x）^8×（y^6）^(1/2)（x⁴× y⁴）²×y⁴
=x^8×y³×(x^8×y^8)×y^4
=x^16y^15
3
（x-y）^5÷（y-x）⁴
=(x-y)^5÷(x-y)⁴
=x-y
4
10^a=5,10^b=6
(1)
10^(2a+3b)
=10^(2a)*10^(3b)
=(10^a)^2*(10^b)^3
=5^2*6^3
=25*216
=5400
(2)
10^(2a)+10^(3b)
=25+216
=241