strange, in another problem you had exactly the opposite problem. you could set up the equation but couldn't solve

anyway. write the percentages as decimals. (remember, "percentage" means divided by 100, so 25% = 25/100 = 0.25, for example).

Let be the amount of juice in brand A (we can convert to percentage when finished)

we have 8 gal of brand B where 48% = 0.48 of it is juice. thus, the amount of juice in B that is juice is (0.48)8 = 3.84

similarly, we want, 0.3(17) = 5.1 gal of the mixture to be juice.

again, similarly, the amount of juice in A is given by

thus we have:

now solve for x and you can get the rest i think