I don't know for sure I'm going to ace grade next year but I know that you you need to put the coefficients with the same variable together and the variable next to the coefficients and multiply or add or divide or subtract them and you get your answer and this is just 7th grade math I'm relying on
sadly i haven’t learned this so i can’t help you with the answers themselves but a graphing utility you could use is a graphing calculator or a graphing calculator online i know one called desmos.com just not sure if it has the intersect feature so i recommend graphing calculator