## Elementary and Intermediate Algebra: Concepts & Applications (6th Edition)

Equation 1 variable y isolated - select the substitution method. $y=\displaystyle \frac{5}{3}x+7\qquad$(*) Replace y with $\displaystyle \frac{5}{3}x+7$ in the second equation: $\displaystyle \frac{5}{3}x+7=\frac{5}{3}x-8\qquad$ ... and solve for $x$. ...add $-7-\displaystyle \frac{5}{3}x$ to both sides $0=-15\qquad$ ... a contradiction. The system has no solution (the graphs of the equations are parallel lines, no intersections.)