4x+15=75 in a number line

The scatter plot graph shows the average annual income for a certain profession based on the number of years of experience which of the following is most likely to be the equation of the trend line for this set of data? a. i=5350e +37100 b. i=5350e-37100 c. i=5350e d. e=5350e+37100

An appliance store sells a washer-dryer combination for $1800. if the washer costs $300 more than the dryer, find the cost for each appliance.

How do you use the elimination method for this question? explain, because i really want to understand!