Plz help urgent 20 PTS

Before simplifying, how many terms are there in the expression 2x - 5y + 3 + x?

Which equation results from adding the equations in this system? x+6y=9 and -x+2y=-15

What is the probability of throwing several dice with sum equal to 6 (six)? show the ways of possibilities for sum 6 (as the numerator) and the ways of throwing n dices for n = 1, 2, 3, 4 or 5 as denominator for all the questions to earn full credits. (a)throw one die, (b) throw two dice, (c) throw three dice (d) throw 4 dice, (e) throw 5 dice