First begin with rearranging the second equation to put it in terms of Y. Then substitute by putting the second equation (y=3x+13) into equation one as Y^2. Expand (3x+13)^2 and add like terms to form 10x^2 + 78x + 144 =0. Simplify and fractionise to get the terms of x=-3 and x= -24/5. Finally substitute each term of X into the original equation of (y=3x+13) to get the Y terms of Y=4 and Y=-3/5