(2.4m^2-0.8n^2)(0,8n^2+2.4 m^2)

(1.3x^3-1.8y^2)(1.8y^2+1.3x^3)

(2,4m² - 0.8n²)(0.8n²+2.4m²)=5.76m⁴-0.64n⁴=0.64(9m⁴-n⁴)(1.3x³-1.8y²)(1.8y²+1.3x³)=1.69x⁶ - 3.24y⁴