I need help with math
1 answer:
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we know that
A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form y/x=k or y=kx
so
That means it's the equation of a line passing through the origin.
case a) and case d) are discarded because the line does not pass through the origin
<u>case b) we have</u>
for x=2 y=4
y/x=k-------> 4/2=2------> k=2
y=2x-------> in this case the value of y is two times the value of x
<u>case c) we have</u>
for x=4 y=2
y/x=k-------> 2/4=1/2------> k=(1/2)
y=(1/2)x-------> in this case the value of y is one-half of the value of x
therefore
the solution is the case c) see the attached figure
So, how much acid is there in 6 gallons? well is 20% acid or (20/100), so the amount of acid in it just (20/100) * 6 or 1.2, the rest is say water.
now, if we want a 90% solution, and say we add "y" gallons, how much acid is in it? well (90/100) * y, or 0.9y.
now let's add "x" gallons of pure acid, now, pure acid is just pure acid, so is 100% acid, how much acid is there in it? (100/100) * x, or 1x or just x.
we know whatever "x" and "y" amounts are, they -> x + 6 = y
and we also know that x + 1.2 = 0.9y
now, if we want a 90% solution, and say we add "y" gallons, how much acid is in it? well (90/100) * y, or 0.9y.
now let's add "x" gallons of pure acid, now, pure acid is just pure acid, so is 100% acid, how much acid is there in it? (100/100) * x, or 1x or just x.
we know whatever "x" and "y" amounts are, they -> x + 6 = y
and we also know that x + 1.2 = 0.9y