Answer:
Step-by-step explanation:
[tex]\text{The equation of a linear function:}\\\\f(x)=mx+b\\\\m-slope\\b-y-intercept\\----------------------------\\\\A.\ f(x)=\dfrac{2}{x}+7\qquad\bold{NOT}\ /\text{x is in denominator}/\\\\B.\ f(x)=\sqrt{2+7x}\qquad\bold{NOT}\ /\text{x is under square roots}/\\\\C.\ f(x)=2-7x\qquad\bold{YES}\ /m=-7,\ b=2/\\\\D.\ f(x)=2+x+x^2\qquad\bold{NOT}\ /\text{x is in the second power}/[/tex]