C2+d3, if c=8 and d=-3

Which equation results from adding the equations in this system? x+6y=9 and -x+2y=-15

Acar started driving from city a to city b, distance between which is 620 miles, at a rate of 60 mph. two hours later a truck left city b and started moving towards city a at a rate of 40 mph. what distance from city a is the point where the truck and the car will meet?

Write the equation in logarithmic form 8^x=64