Explanation:
2x + 10y = 50 ... 1
1.5x + 25y = 90 ...2
...1 × 2.5
5x + 25y = 125 ...3
...3 - ...2
3.5x = 35
x = 10
replaced x = 10 in ...1
2(10) + 10y = 50
20 + 10y = 50
10y = 50 - 20
10y = 30
y = 3
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