Answer:
3x = 0
Step-by-step explanation:
Given,
y = 10
now,
5x+2y = 20
or, 5x+2×10=20
or, 5x = 20-20
or, 5x = 0
or, x = 0/5
or, x = 0
Again,
3x = 3×0 =0
