Question 64828
Let x=number of pounds of the $6.00 brand
Then 30-x=number of pounds of $7.50 brand


Now we know that the amount of money generated by the $6.00 brand ($6.00)(x) plus the amount of money generated by the $7.50 brand (30-x)($7.50) must equal the amount of money generated by the final blend (30)($7.00) so our equation to solve is:


6.00(x)+7.50(30-x)=(30)(7.00) simplifying we have:

6x-7.5x+225=210 collecting like terms we get:
-1.5x=-225+210=-15
x=10 lb for the $6.00 brand
30-x=30-10=20 lb for the $7.50 brand

ck
6.00(10)+7.50(30-10)=30(7.00)
60+150=210
210=210

Hope this helps.  Happy holidays.--------ptaylor