Hi there!
The answer is D.
We need to isolate each square root. We can simply do this by adding

to both sides of the equation.
When we isolated the square roots, our equation looks like this:

Now we can easily square both sides of the equation, which would have been much harder earlier.
~ Hope this helps you!
Collin invested $5529 in the account paying 2% and $2171 in the account paying 9% interest.
<u>Explanation:</u>
Let x be amount invested at 2%
So, 7700 - x will be the amount invested at 9%
0.02(x) + 0.09(7800 - x) = 315
0.02x + 702 - 0.09x = 315
-0.07x = -387
x = $5529
7700 - x = 7700 - 5529
= $2171
Collin invested $5529 in the account paying 2% and $2171 in the account paying 9% interest.
Step-by-step explanation:
12 feet is true.......
You can make the equation 12x=156-x
Then from there it become 13x=156
So x=12
It is a step function. The question is from a practice test right?