X= # gallons of pure water that should be evaporated
The total amount of salt must be equal before and after evaporation.
STEP 1
BEFORE EVAPORATION: multiply the percent of salt in the solution before evaporation by the total gallons of solution
= 12% * 160 gallonsconvert 12% to decimal form (12% ÷ 100)
= 0.12 * 60
STEP 2
AFTER EVAPORATION: subtract the number of gallons of pure water that should be evaporated from the total number of gallons of the solution and multiply by the percent of salt in the solution after evaporation
= 20% * (160 - x)convert 20% to decimal form (20% ÷ 100)
= 0.20(160 - x)
STEP 3
Set the before & after evaporation equations equal to one another to solve for x.
0.12 * 160= 0.20(160 - x)multiply 0.20 by each term in parentheses
19.2= (0.20 * 160) + (0.20 * -x)multiply in parentheses
19.2 = 32 - 0.20xsubtract 32 from both sides
-12.8= -0.20xdivide both sides by -0.20
64 gallons= x
CHECK:substitute x= 64 into the step 3 equation
0.12 * 160= 0.20(160 - x)19.2= 0.20(160 - 64)subtract in parentheses19.2= 0.20(96)19.2= 19.2
ANSWER: 64 gallons of pure water should be evaporated.
Hope this helps! :)
We have been given a polynomial and we are asked to factor our polynomial by double grouping.
First of all we will group terms with common factors. We can see that 
and 2x have a common factor x. Common factor of -3x and -6 is -3.
Now we will factor out Greatest Common Factor from each group.
After factoring out GCF from each group we got (x+2) as our common binomial. Now we will write our polynomial as a product of two binomials as:
Therefore, our polynomial as a product of two binomials will be .
Answer:
A=1/2(b)(h)
Step-by-step explanation:
A=1/2(7)(6)
A=21
Here’s the completed graph from desmos
