Question 67822

Let x=amount of pure orange juice that needs to be added

Now we know that the amount of pure orange juice in the 10% mixture (0.1)(5) plus the amount of pure orange juice added (x) has to equal the amount of pure orange juice in the final mixture (0.4)(5+x).  Our equation to solve:

(0.1)(5)+x=(0.4)(5+x)  clear parens

0.5+x=2+0.4x  subtract 0.4x and 0.5 from both sides

0.5-0.5+x-0.4x=2-0.5+0.4x-0.4x  collect like terms

0.6x=1.5

x=2.5 gal-------------------------ans

ck
substitute x=2.5 into original equation
(0.1)(5)+2.5=.4(7.5)
3=3


Hope this helps----ptaylor