Answer:
D. 0.925x + 0.88y = 0.91(x + y)
Step-by-step explanation:
The important point to remember is that the total mass of pure silver is the same on each side of the equation.
0.925x = mass of pure silver in first alloy
0.88 y = mass of pure silver in second alloy
The final alloy has a mass of (x + y) g and is 91 % pure silver, so
0.925x + 0.88y = 0.91(x + y)
Am going to presume you want it solved.
Please pardon my presumption
7 - (2/3)x < x - 8, Take all the x to one side of the inequality
-(2/3)x-x < - 8 -7
-(5/3)x < - 15 Divide both sides by -5/3 and inequality sign changes
x > (-15)/(-5/3)
x > 15 * 3/5 . 5 into 15 is 3.
x > 3*3
x > 9
To find which ratio is higher, we can first convert the ratios into fractions (that makes it easier, at least for me) and then simplify the fractions and see which one is greater.
Since ratios are basically division, 15:20 = 
, and
12:16 = 
Now we simplify these fractions. 15 and 20 have a GCF of 5, so taking out the common number gives us the simplified fraction of 
.
12 and 16 have a GCF of 4, so taking out the common number gives us the simplified fraction of . Since = , these ratios are the same.
