Answer: 13x^2 - 15x + 12
Step-by-step explanation:
[tex]\left(3x^2-10x+4\right)+\left(10x^2-5x+8\right)[/tex]
[tex]=3x^2-10x+4+10x^2-5x+8[/tex]
[tex]\mathrm{Group\:like\:terms}[/tex]
[tex]=3x^2+10x^2-10x-5x+4+8[/tex]
[tex]\mathrm{Add\:the\:numbers:}\:4+8=12[/tex]
[tex]=3x^2+10x^2-10x-5x+12[/tex]
[tex]\mathrm{Add\:similar\:terms:}\:3x^2+10x^2=13x^2[/tex]
[tex]=13x^2-10x-5x+12[/tex]
[tex]\mathrm{Add\:similar\:terms:}\:-10x-5x=-15x[/tex]
[tex]=13x^2-15x+12[/tex]
