y=x^2-5
dy=(x^2-5)`dx
dy=2xdx
[m]= ∫ ^{2}_{1}(2\cdot (x^2-5)dx+(x^2-5+3x^2)\cdot 2xdx)=∫ ^{2}_{1}(2x^2-10+2x^3-10x+6x^3)dx=[/m]
[m]=∫ ^{2}_{1}(8x^3+2x^2-10x-10)dx=(8\frac{x^4}{4}+2\frac{x^3}{3}-10\frac{x^2}{2}-10x)|^{2}_{1}=(8\frac{2^4}{4}+2\frac{2^3}{3}-10\frac{2^2}{2}-20)-(8\frac{1^4}{4}+2\frac{1^3}{3}-10\frac{1^2}{2}-10)=\frac{29}{3}=9\frac{2}{3}[/m]