What does the expression l+w+l+w represent

If f(x)=-x^2+6x-1 and g(x)=3x^2-4x-1,find(f+g)(x)

Which number completes the inequality? 2/3 < _ < 7/9

Type the correct answer in the box. consider the system of linear equations below. rewrite one of the two equations above in the form ax + by = c, where a, b, and c are constants, so that the sum of the new equation and the unchanged equation from the original system results in an equation in one variable.