2x + 7 ≤ 3x - 5
Start by keeping the variable x on the left side of the inequality, and move everything else to the right side.
We can do this by subtracting 3x from both sides and subtracting 7 from both sides.
-x ≤ -12
Divide both sides by -1 to make x a positive; when dividing by a negative number you will flip the inequality sign, so ≤ becomes ≥.
x ≥ 12
Possible solutions for x are any number equal to or greater than 12.
20% of x=6
20/100 of x=6
20x= 600
x=30
38% of 30=11.4
4 is the constant varriation
Answer:
The answer is
Step-by-step explanation:
Let x gallons be the amount of pure antifreeze that should be added to the 30% solution to produce a solution that is 65% antifreeze. Then the total amount of antifreeze solution will be x+3 gallons.
There are 30% of pure antifreeze in 3 gallons of solution, then
3 gallons - 100%,
a gallons - 30%,
where a gallons is the amount of pure antifreeze in given solution.
Mathematically,

Now in new solution there will be x+0.9 gallons of pure antefreeze.
x+3 gallons - 100%,
x+0.9 - 65%
or

Answer: he should add 3 gallons of pure antifreeze.