Answer:
-x+4, 4+-x
Step-by-step explanation:
Obtain these answers by moving the X and 4 around and multiplying the equation by -1
Answer:
- $12,000 at 4%
- $9,000 at 2%
Step-by-step explanation:
If x represents the amount invested at 4%, then the total interest earned is ...
0.04x + 0.02(21000 -x) = 660
0.02x = 240 . . . . . . . . . . . simplify, subtract 420
x= 240/0.02 = 12,000 . . . . amount invested at 4%
21,000 -x = 9,000 . . . . . . . . amount invested at 2%
The amount invested at 2% is $9,000.
The amount invested at 4% is $12,000.
_____
<em>Comment on method of solution</em>
These problems can usually be solved using one variable for the amount associated with the highest contribution to the mix. Here, that is the amount getting 4% interest. This keeps the numbers in the solution positive, helping to minimize errors. As you can see, the solution develops in about 2 or 3 steps. Other methods can take longer.
nothing can further be done with this?
Answer:
Brady did not distribute the -1 correctly.
Step-by-step explanation:
The given expresion is
![2.6 - (1.3 - 4.5)](https://tex.z-dn.net/?f=2.6%20-%20%281.3%20-%204.5%29)
Recall that for all real numbers a, b, and c, the distributive property says that:
![a(b + c) = ab + ac](https://tex.z-dn.net/?f=a%28b%20%2B%20c%29%20%3D%20ab%20%2B%20ac)
We apply this property to get:
![2.6 - (1 .3 - 4.5) = 2.6 - 1.3 + 4.5](https://tex.z-dn.net/?f=2.6%20-%20%281%20.3%20-%204.5%29%20%3D%202.6%20-%201.3%20%2B%204.5)
![2.6 - (1 .3 - 4.5) = 1.3 + 4.5](https://tex.z-dn.net/?f=2.6%20-%20%281%20.3%20-%204.5%29%20%3D%201.3%20%2B%204.5)
But Brady said it is equivalent to 1.3-4.5
Hence Brady did not apply the distributive property correctly.