SmolBeanPotato SmolBeanPotato 06-03-2019 Mathematics contestada Please help me!! 1. -2x + 4x^2 - 7 - x^2 + 7 - 8x 2. 7ab - bc - 4ab - 5bc 3. 3x^2 - 5x + 7 + 2x^2 + 3x - 9 4. 3r + 2z + 9t + 4r - 5s + t 5. -5xy + 7wz - xy - 5wz