"Each plan utilizes a combination of 2 strength-training sessions and 2 aerobic exercise sessions per week." because. Let n be the number of aerobic and strength-training exercises per week. Let x be the number of strength-training exercises per week on the beginner
15x + 20n = 90
Let y be the number of strength-training exercises for week on the advanced plan. 20y + 30n = 130
Multiply both sides by 1.5, to get: 22.5x + 30n = 135 Subtracting equation 2 from 3 we get: 22.5x - 20y = 5
