﹙a+b-2c﹚^2 ﹙a-b﹚^2﹙a+b﹚^2﹙a^2+b^2﹚^2 ﹙7m^2﹚*﹙4m^4p﹚÷﹙7m^6﹚ ﹙-38x^4y^5z﹚÷﹙19xy^5﹚×﹙﹣3/4x^3y^2﹚﹙4a^2x^2﹚*﹙﹣2/5a^4x^y^3﹚÷﹙﹣1/2a^5xy^2﹚﹙﹣6×10^3﹚÷﹙12×10^2﹚×﹙2×10﹚