Answer:
You need to solve for one variable in each equation and the substitute that in for the second equation.
Step-by-step explanation:
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:
You chose correctly
Step-by-step explanation:
Answer:
9.2%
Step-by-step explanation:
227/250= .908
1.00-90.8=9.2
Answer:
Step-by-step explanation:
3*2 * 4 * 9 =36 * 6 = 216
216 ( 4 < 7)
864 < 1512