Answer:
31.5 m^2
Step-by-step explanation:
To find the amount for 7 bags, create a proportion.
[tex]\frac{4}{18} =\frac{7}{y}[/tex]
To solve for y, cross multiply numerator to denominator of each fraction.
4(y) = 18(7)
4y= 126
y= 31.5
7 bags will do 31.5 m^2