Answer:
simplify 36 - 4.5x + 36 to -4.5x + 72
simplify 102 - 7.5x - 60 to -7.5x + 42
add 7.5x to both sides
simplify -4.5x + 72 + 7.5x to 3x + 72
subtract 72 from both sides
simplify 42 - 72 to -30
divide both sides by 3
simplify 30/3 to 10
Answer: x = -10
Answer:
She would make $35.
Step-by-step explanation:
If you do 10 x 3.5, you will get the answer of $35.
Let’s call the number of gallons of 30% solution “x”. If we mix together 40 gallons and x gallons of solution, we’re going to come out with a total of 40 + x gallons of that 20% solution. Mathematically, this is
40(12%) + x(30%) = (40 + x)(20%)
With the percents as decimals:
40(0.12) + x(0.3) = (40 + x)(0.2)
Simplifying, we have:
4.8 + 0.3x = 8 + 0.2x
Collecting the x terms on one side and the constants on the other:
0.1x = 3.2
And multiplying both sides by 10 to find x:
x = 32
So, you’ll need 32 gallons of 30% solution to yield 40 + 32 = 72 gallons of 20% solution.
