Solve 6k + 9 > k – 1. k > -3 k > -5 k > -4 k

How much pure acid should be mixed with 6 gallons of a 20% acid solution in order to get a 90% acid solution?

beks73 [17]

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

$\bf \begin{array}{lccclll}
&\stackrel{gallons}{acid}&\stackrel{acid~\%}{quantity}&\stackrel{acid~gallons}{quantity}\\
&------&------&------\\
\textit{pure acid}&x&1.00&x\\
\textit{20\% sol'n}&6&0.20&1.2\\
------&------&------&------\\\
mixture&y&0.90&0.9y
\end{array}
\\\\\\
\begin{cases}
x+6=\boxed{y}\\
x+1.2=0.9y\\
----------\\
x+1.2=0.9\left( \boxed{x+6} \right)
\end{cases}
\\\\\\
x+1.2=0.9x+5.4\implies x-0.9x=5.4-1.2\implies 0.1x=4.2
\\\\\\
x=\cfrac{4.2}{0.1}\implies x=\stackrel{gallons}{42}$

3 0

3 years ago

1.ayah bersepeda motor ke rumah nenek yang jaraknya 9 km dalam waktu 15 menit.berapa km / jam kecepatan sepeda motor?

Helen [10]

Halkalar ne zaman istersen gel ben

5 0

3 years ago

Type the correct answer in each box. Use numerals instead of words. If necessary, use / for the fraction bar(s). Consider the gi

STatiana [176]

Answer:

To determine the inverse of the given function, change f(x) to y, switch x and y and solve for y and $f^{-1}(x)= \frac{ln\ x+4}{2}$

Step-by-step explanation:

Data provided in the question

f(x) = e^2x - 4

Now

to find the inverse let

So,

y = e^2x - 4

Now

Replace x and y

Therefore

x = e^2y - 4

Now compute the value of y

So,

x + 4 = e^2y

Now take ln on both sides:

The equation is

ln(x+4) = ln(e^2y)

ln(x+4) = 2y

y = ln(x+4) ÷ 2

$f^{-1}(x)= \frac{ln\ x+4}{2}$

Therefore, To determine the inverse of the given function, change f(x) to y, switch x and y and solve for y and $f^{-1}(x)= \frac{ln\ x+4}{2}$

5 0

3 years ago

A watermelon that weighs 9 pounds costs $4.50. What is the price per pound?

allsm [11]

Answer:

0.5 cents per pound.

4.50/9 = 0.5

Please mark me brainliest! I hope this helps!

7 0

2 years ago

Read 2 more answers

2. Find the measure of each numbered angle

miskamm [114]

2) 4 = 90
5 = 45
6 = 45

16) this one's a bit long :)

PLEASE READ
I MADE A DUMB MISTAKE WHEN WORKING OUT THE HEIGHT
ITS NOT 8.41 ITS 9
SORRY ABOUT THAT

3 0

3 years ago

Read 2 more answers

Solve 6k + 9 > k – 1. k > -3 k > -5 k > -4 k > -2