Answer:
The correct answer is A. 167 milliliters of 7% solution and 333 milliliters of 4% solution and here is how:
If x is the number of milliliters of the 7% saline solution and y is the number of milliliters of the 4% saline solution then add up to 500 milliliters total, so x + y = 500.
and if we do
x + y = 500
x = 500 - y
0.07x + 0.04y = 25 (substitute 500 - y for x)
0.07(500 - y) + 0.04y = 25
35 - 0.07y + 0.04y = 25
-0.03y + 35 = 25
-0.03y = -10
y = 333.333...
y = about 333
x = 500 - y = 500 - 333 = 167
Then you know why the answer is A.
Step-by-step explanation:
<span>6.8 x 10^-2
The scientific notation of 70, 030, 000. To find the scientific notation of this value </span><span><span>
1. </span>We first move the period which separates the whole number from the decimal number which is located after the numbers of the given value.</span>
<span><span>2. </span>We move it in the very recent order number which is seventy million, seven and zero.</span> <span><span>
3. </span>It becomes 7.003</span>
<span><span>4. </span>Thus we count how many moves we did from the tens to the ten million order place.</span> <span><span>
5. </span>7.003 x 10^7<span>
</span></span>
There should be only be one step necessary
(4m-1) / m=4-1/m
The tax is $3.42.
I used proportions to find the answer.
Part Percent
——— = —————.
Whole 100
Then, cross multiply.
Part • 100
—————
Percent • Whole
Finally, divide the numerator by the denominator. If you apply these steps to your problem, you will get $3.42.