Chapter 3 - Linear and Quadratic Functions - 3.1 Properties of Linear Functions and Linear Models - 3.1 Assess Your Understanding - Page 129: 50

a. $C(x)=30+0.50(x-80)$ b. $105$ minutes: $42.50$ $dollars$ $\enspace$ $120$ minutes: $50$ $dollars$

a. $C(x)=30+0.50(x-80)$ b. $105$ minutes $\qquad$ $C(x)=30+0.50(x-80)$ $\qquad$ $C(105)=30+0.50(105-80)$ $\qquad$ $C(105)= 42.50$ $\quad$ $120$ minutes $\qquad$ $C(x)=30+0.50(x-80)$ $\qquad$ $C(120)=30+0.50(120-80)$ $\qquad$ $C(120)= 50$