4.
-4(2x+5)=-4(2·(-2)+5))=-4(-4+5)=-4·1=-4
5.
2,4xy²·(-2,5)x²y³=-2,4xy²·2,5x²y³=-6xy²x²y³=-6x¹⁺²y²⁺³=-6x³y⁵
