Which of the following shows that polynomials are closed under addition when two polynomials 4x2 − 8x − 7 and −5x + 16 are added?

4x2 − 13x + 9; may or may not be a polynomial
4x2 + 13x − 23; may or may not be a polynomial
4x2 − 13x + 9; will be a polynomial
4x2 + 13x − 23; will be a polynomial

Which ratio is equivalent to 10: 85

Simplify 5 square root of 7 end root plus 12 square root of 6 end root minus 10 square root of 7 end root minus 5 square root of 6 . (1 point) 5 square root of 14 end root minus 7 square root of 12 5 square root of 7 end root minus 7 square root of 6 7 square root of 12 end root minus 5 square root of 14 7 square root of 6 end root minus 5 square root of 7

Which term best describes the association between variables a and b