
so hmm notice, we use the decimal format for the percent, namely 15% is just 15/100 and 5% is just 5/100 and so on
whatever the amounts of "x" and "y" are, they must add up to 100 grams
thus x + y = 100
and whatever the concentrated amounts are, they'll add up to (100)(0.15)
thus

solve for "x", to see how much 5% alloy will be needed
what about "y"? well y = 100 -x
Answer:
65
Step-by-step explanation:
Answer:
Hi there!
Your answer is:
81
Step-by-step explanation:
First, simplify within parentheses.
-4-3-2 = -7-2 = -9
(-9)^2
The negative is within the parentheses, so it goes away when squared
(-9)^2 = -9× -9= 81
Hope this helps
Answer:
2/15
Step-by-step explanation:
Given that she have already read one-third of the book.
The fraction f of the book that will remain is;
f = 1 - 1/3 = 2/3
Then she finishes the book by reading the same amount each night for 5 nights
That implies she reads the remaining 2/3 of the book at equal rates for 5 nights.
Let x represent the fraction rate read per night;
5x = 2/3
Divide both sides by 5
x = 2/3 × 1/5
x = 2/15
Therefore, she reads 2/15 of the book every night for 5 nights.