If 3x +15 = 21, then what is the value of x + 5?

Aregression was run to determine if there is a relationship between hours of tv watched per day (x) and number of situps a person can do (y). the results of the regression were: y=ax+b a=-0.662 b=30.418 r2=0.703921 r=-0.839

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

Explain why the factor 1.5 is broke. into two numbers in the model.