Tính: a) (-2)^2.(-2)^3; b) (-0,25)^7 . (-0,25)^5; c) (3/4)^4 . (3/4)^3

a) (-2)².(-2)³ = (-2)^{2 + 3} = (-2)⁵;

b) (-0,25)⁷.(-0,25)⁵ = (-0,25)^{7 + 5} = (-0,25)¹²;

${\left(\frac{3}{4}\right)}^4.{\left(\frac{3}{4}\right)}^3={\left(\frac{3}{4}\right)}^{4+3}={\left(\frac{3}{4}\right)}^7$