Answer:
13.5
Step-by-step explanation:
Siince 2nd equation is already equal a, subsitute b-2 for a in the other equation
b-2-3b=28
-2-2b=28
add 2 to both sides
-2b=30
divide both sides by -2
b=-15
sub back
a=b-2
a=-15-2
a=-17
(a,b)
(-17,-15)
3rd choice
Answer:
no clue
Step-by-step explanation:

notice, that, pure juice is 100% juice, dohhh, thus 100/100 = 1.00
50% is 50/100 or 0.50 in decimal format
so..... whatever those two quantities amount to, that is, the 50% and pure juice, or (4)(0.50) + (x)(1.00)
they will equal the mixture desired 60% juice, or 0.60, namely (4+x)(0.60)
thus (4)(0.50) + (x)(1.00) = (4+x)(0.60)
solve for "x"