a)
5x^4y*(-3x²y³) =-15x^6y^4
b)
(-7)²*(-3/7)^-3 = (-7)² * (-7/3)³ = -49*243/27 = - 49*9=-441
c)
(-2xy^4)^4=16x^4y^16
d)
10x^(-2)y^4 *5^(-1)x^4y^(-1) = 10*1/5*x²y³
e)
3,4x^6y^(-4) / 1,7x^(-8)y^(-1) = x^14 y^(-3)
f)
(-2a^2b^3)^4 * (-0,5ab^4)^3 = 16a^8b^12 *-0,125a^3b^12=-2a^11b^24
g)
(-2 ½ a³b)^4 * 3 1/5 a^8b^5=( 5/2)^4a^12b^4 * 16/5a^8b^5=625/16*16/5 a²0b^9=125a^20*b^9
h)
[3k / x^(-2) ]^(-2)= [x^(-2) / 3k^4 ]²= x^(-4) / 9k^16
i)
x^2n / [x^(n-1)]^2=x^2n / x^(2n-2) = x^(2n-(2n-2)=x²