Please help and show step by step

Answer:
75 students
Step-by-step explanation:
(70% Students)
(100 Students Left)
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x = number of students left
[tex]\frac{70-x}{100-x}[/tex] = .6
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multiply by (100-x)
70 - x = .6 (100 - x)
70 - x = 60 - .6x
70 - 60 = x - .6x
10 = .4x
x = 10/.4
x = 25
Then, you subtract 25 from 100.
100-25 = 75 students