How do i simplify the polynomial

(-8x^3y^4-7x^3y^3)+(-3x^3y^3-8x^3 y^4)

Could someone me? it's about drink looking at the effects and consequences of illegal drinking, what advice would you give an 11-year-old brother or sister? list at least three effects/consequences, and be specific by using examples.

Why girls are tan and why they fake tan

Which many - celled organisms are capable of causing diseases in humans