## Elementary Algebra

Let X represent the pounds of salt needed for 25 gallons of water. Now, let’s set up a proportion in which one ratio compares the amounts of salt and the other ratio compares the amounts of water. So, $\frac{3}{X}$ = $\frac{10}{25}$ To solve this equation, we equate the cross products. 3 $\times$ 25 = X $\times$ 10. 75 = 10X Divide both sides by 10. X = 7.5 7.5 pounds of salt are needed for 25 gallons of water.