Question

Tenisha solved the equation below by graphing a system of equations. log3 5x=log5 (2x+8) Which point approximates the solution for Tenisha’s system of equations?

Answer 1

The answer is B. (1.0, 1.4)

Answer 2

You can use grahical calculator to plot both graphs (see attached image). As you can see, the x-coordinate of intersection point is somewhere nearly 2.75, then you can calculate y-coordinate (or approximately count it from the diagram).

1. $\log_3 (5\cdot 0.95)=\log_3 4.75\approx 1.42$;

2. $\log_5 (2\cdot 0.95+8)=\log_5 9.9\approx 1.42$.

Therefore, point (0.95, 1.42) approximates the solution for Tenisha’s system of equations.