How do you solve the systems by substitution y=3x+1 and y=5x-3

Venus is about 108 kilometers from the sun. saturn is about 109 kilometers from the sun. about how many times farther from the sun is saturn than venus?

Kelly is a salesperson at a shoe store, where she must sell a pre-set number of pairs of shoes each month. at the end of each work day the number of pairs of shoes that she has left to sell that month is given by the equation s=300-15x , where s is the number of pair of shoes kelly still needs to sell and x is the number of days she has worked that month. what is the meaning of the number 300 in this equation

One integer is 5 more than another. their product is 104. find the integers