Sarah went into the local Dollar Store because they have so many deals!! The following deal that she was debating is 4 bars of soap that cost $5. What would 8 bars cost her?

-2 is the right

step-by-step explanation:

one of the most important purposes of surface treatment is to alter surface properties according to the requirement of specific applications. for example, hydrophobic coating has been utilized on windshield and eyeglasses. gold atom monolayer on substrate has become a popular surface bioconjugation strategy.  

cross multiplying, we get :

⇒ (3) × (5) = (9) × (x)

⇒ 15 = 9x