Andrew lent roger $4800 for 7months. at the end of this period roger had to pay andrew an investment of $119. what was the rate of simple interest per annum

Will mark 50 show all what is the solution to the system of equations? use the substitution method and show your work. -5x+y= -3 -15 x+3y=7 explain what your answer in part (a) tells you about the association of the lines in this system.