The amount of grams that she must use to make the solution she needs are: 12 grams and 8 grams.
x grams of 20% and 20-x grams of 35%
Hence:
0.20x+0.35(20-x)=0.26×20
0.20x-0.35x+7=5.2
Collect like terms
-0.15x=-1.80
Divide both side by -0.15x
x=-1.80/-0.15
x=12 grams of 20% or 2.4 grams pure
20-x= (20-12) =8 grams of 35% or 2.8 grams pure
Therefore the amount of grams that she must use to make the solution she needs are: 12 grams and 8 grams.
Learn more about amount of grams here:https://brainly.com/question/1107267
#SPJ1