Set up an equality.
"sum," "and" means to add, and "at least" means greater than or equal to.
5x + 2x ≥ 70
7x ≥ 70
x ≥10
Remember in inequalities you solve them almost like normal equations (you can add, and subtract the same) BUT if you multiply by a negative you must flip the sign. You don't have to flip the sign in this case because there are no negatives.
