Answer:
$2353 at 12.5% and $7647 at 8.25%
Step-by-step explanation:
I'll say a is the amount he invested in one market, and b is the amount in the other.
a + b = 10000, or b = 10000 - a
multiplying the investments with the percentages and adding them together will give the total earned interest.
(a × 0.125) + (b × 0.0825) = 925
0.125a + 0.0825b = 925
Use substitution to solve for a.
0.125a + 0.0825(10000 - a) = 925
0.125 a + 825 - 0.0825a = 925
0.0425a = 100
a = 2352.94
Use substitution to find b
b = 10000 - 2352.94
b = 7647.06
The questions are to the nearest dollar so round a and b.
$2353 and $7647
There is a 60% chance that the product of the two numbers will be 7 because the numbers 1-6 are each 10% of the 100%.
x
=
−
8
,
−
2
Explanation:
Given:
x
2
+
10
x
+
16
=
0
To complete the square put the two
x
terms on the left and the constant on the right of the equation:
x
2
+
10
x
=
−
16
Complete the square by multiplying the
x
-term by
1
2
:
1
2
⋅
10
=
5
and adding the square of this number to the right side of the equation:
5
2
=
25
(
x
+
5
)
2
=
−
16
+
25
UNDERSTANDING CHECK:
(
x
+
5
)
2
=
x
2
+
10
x
+
25
.
The
+
25
was not in the original equation. If we add
+
25
to one side of the equation, we must add the same amount to the other side of the equation to keep it balanced.
(
x
+
5
)
2
=
9
To solve, square root both sides of the equation:
√
(
x
+
5
)
2
=
±
√
9
x
+
5
=
±
3
x
=
−
5
±
3
x
=
−
5
+
3
=
−
2
,
x
=
−
5
−
3
=
−
8
x
=
−
8
,
−
2
9514 1404 393
Answer:
4%
Step-by-step explanation:
The simple interest formula can be used.
I = Prt
where r is the annual rate and t is the number of years.
1/5 = 1·r·5
(1/5)/5 = r = 1/25 · 100% = 4%
The rate is 4%.
