Concentration = [ (mass of sugar)/(mass of solution) ] * 100
=> mass of solution = mass of sugar * 100 / concentration
1) concentration 20%
mass of sugar = 0.5 lbs
=> mass of solution = mass of sugar * 100 / concentration = 0.5 lbs * 100 / 20
mass of solution = 2,5 lbs
mass of water = mass of solution - mass of sugar = 2.5 lbs - 0.5 lbs = 2.0 lbs
Answer: she must add 2.0 lbs of water and will obtain 2.5 lbs of syrup
2) concentration 25%
Follow the same procedure.
mass of solution = 0.5 lbs * 100 / 25 =
mass of solution = 2.0 lbs
mass of water = 2.0 lbs - 0.5 lbs = 1.5lbs
Answer: she has to add 1.5 lbs of water and will obtain 2.0 lbs of syrup
3) Same procedure
mass of solution = mass of sugar * 100 / concentration = 0.5 lbs * 100 / 1.5
mass of solution = 33.33 lbs
mass of water = 33.33 lbs - 0.5 lbs = 32.83 lbs
Answer: she has to add 32.83 lbs of water and will obtain 32.83 lbs of syrup
(3x²-2x-4)(2x²+x-3)=3x²(2x²+x-3)-2x(2x²+x-3)-4(2x²+x-3)=
=6x⁴+3x³-9x²-(4x³+2x²-6x)-(8x²+4x-12)=
=6x⁴+3x³-9x²-4x³-2x²+6x-8x²-4x+12=
=6x⁴-x³-x²+2x+12
Answer:
for them points
Step-by-step explanation:
B.) 12
(13-1) =12
12 • (-6) = -72
84 + -72 = 12