You have two people answer and whoever answer you think is better you can mark them as brainliest
Answer:
10
Step-by-step explanation:
We will use a system of equations to solve this. We do not know how much of the 25% bleach solution is used; we will use x to represent this. We know that 5 cups of the 10% solution was used. We do not know how much of the resulting solution we have; we will use y to represent this. This gives us the equation
x+5 = y
Using the decimal forms of the percentages for each solution, we have 0.25x (25% solution for x cups), 0.1(5) (10% solution for 5 cups) and 0.2y (20% solution for y cups); this gives us the equation
0.25x+0.1(5) = 0.2y
This gives us the system

To use elimination, we will make the coefficients of x the same by multiplying the top equation by 0.25:

We will now subtract the second equation from the first:

Divide both sides by 0.05:
0.75/0.05 = 0.05y/0.05
15 = y
There were 15 cups of the resulting 20% solution. Substituting this into the first equation, we have
x+5=15
Subtract 5 from each side:
x+5-5=15-5
x = 10
Answer:
°
Step-by-step explanation:
Use the Law of Sines as follows:

Insert the appropriate values:

Isolate B. Multiply both sides by 11:

Use the inverse:

Insert the equation into a calculator and round to the nearest degree:

Angle B is 51°.
:Done
Let's take the number as x.
two-fifths of a number = 2x / 5
decreased by 3 = (2x/5) - 3
(2x/5) - 3
(2*25/5) - 3
(2*5) - 3
10 - 3
7
-20
Explanation:
(
−
7 ^
2 − 4
) + (
−
7 ^
2 − 6
−
2
)
Eliminate the redundant parentheses, subtract the numbers which will get you, combine like terms, rearrange terms, then your solution is:
−
1
4
2
−6
−6
Figure that problem out then you will get -20.