Answer:
x = 200
Explanation:
Just substitute 15 in for y and solve for x.
1/5x - 2/3y = 30; y = 15
1/5x - 2/3(15) = 30
1/5x - 10 = 30
1/5x - 10 + 10 = 30 + 10
1/5x = 40
(5)(1/5x) = (40)(5)
x = 200
To check this answer, just substitute the 15 in for y and 200 in for x and simplify. If the left side of the equation comes out to equal 30, the answer is correct.
1/5(200) - 2/3(15) = 30
40 - 10 = 30
30 = 30
This check proves that the answer is correct.
The value of x is 200.
Hope this helps!