Answer:
b = 2(g + r)
Marisa used b = 8 cups of blueberries.
Step-by-step explanation:
Let g be the cups of green grapes, r be the cups of red grapes, and b be the cups o blueberries Marisa used..
then we know that
g = 1 (Marisa used 1 cup of green grapes)
r = 3 (Marisa used 3 cup of red grapes)
g + r = 4
Marisa used twice as may cups of blueberries as cups of grapes; this means
b = 2(g + r )
b = 2(4) = 8
Marisa used 8 cups pf blueberries.
