Cost of one eraser is $3.5.
Step-by-step explanation:
Total money spent by Ronny = $29.50
from which he spent -
Math magazine = $15.50
and four erasers.
Let the cost of one eraser be x
cost of four erasers = 4x
Forming the equation -
[tex]29.50=4x+15.50[/tex]
[tex]4x = 29.50-15.50\\4x=14\\x=14/4\\x= 3.5[/tex]
Cost of one eraser is $3.5.