Answer: D
Step-by-step explanation:
Answer:
$1564 was invested at 5%
$6475 was invested at 10%
Step-by-step explanation:
Let the amount invested at 5% be X
And that invested at 10% be Y.
Interest on X
Interest on Y
From the question,
Interest on Y
Also, from the question, both interests add up to $922.80
Answer:
See explanations below
Step-by-step explanation:
Let the amount of nickel be x
Let the amount of pennies be y
Let the amount of quarters be z
If the the total value of the coins is 3.88, then;
x+y+z = 3.88 .... 1
If Anita has 4 more nickels than pennies, then;
x = y + 4 ... 2
If she has 2 more than 4 times the number of quarters than pennies, then;
y = 2 + 4z
4z = y-2
z = (y-2)/4 ...3
Substitute 2 and 3 into 1
y+4+y+(y-2)/4 = 3.88
4y+16+4y + y-2 = 15.52
9y + 14 = 15.52
9y = 15.52 - 14
9y = 1.52
y = 1.52/9
y = 0.17
Since x = y + 4
x = 0.17+4
x = 4.17
z = y-2/4
z = 0.17-2/4
z = -1.83/4
z = - 0.46
Answer: its b
Step-by-step explanation:
Answer:
(2, 1)
Step-by-step explanation:
The best way to do this to avoid tedious fractions is to use the addition method (sometimes called the elimination method). We will work to eliminate one of the variables. Since the y values are smaller, let's work to get rid of those. That means we have to have a positive and a negative of the same number so they cancel each other out. We have a 2y and a 3y. The LCM of those numbers is 6, so we will multiply the first equation by a 3 and the second one by a 2. BUT they have to cancel out, so one of those multipliers will have to be negative. I made the 2 negative. Multiplying in the 3 and the -2:
3(-9x + 2y = -16)--> -27x + 6y = -48
-2(19x + 3y = 41)--> -38x - 6y = -82
Now you can see that the 6y and the -6y cancel each other out, leaving us to do the addition of what's left:
-65x = -130 so
x = 2
Now we will go back to either one of the original equations and sub in a 2 for x to solve for y:
19(2) + 3y = 41 so
38 + 3y = 41 and
3y = 3. Therefore,
y = 1
The solution set then is (2, 1)