Answer: $12000 was invested at 7% while $8000 was invested at 9%.
Step-by-step explanation:
Based on the information given in the question, let the amount that was invested at 7% be n.
Therefore,
0.07n + 0.09(20000 - n) = 1560
0.07n + 1800 - 0.09n = 1560
-0.02n = 1560 - 1800
-0.02n = -240
n = 240/0.02
n = 120
Therefore, $12000 was invested at 7% while $8000 was invested at 9%.
Answer:
180
Step-by-step explanation:
180 is the left
I assume you're asked to solve
4 cos²(<em>x</em>) - 7 cos(<em>x</em>) + 3 = 0
Factor the left side:
(4 cos(<em>x</em>) - 3) (cos(<em>x</em>) - 1) = 0
Then either
4 cos(<em>x</em>) - 3 = 0 <u>or</u> cos(<em>x</em>) - 1 = 0
cos(<em>x</em>) = 3/4 <u>or</u> cos(<em>x</em>) = 1
From the first case, we get
<em>x</em> = cos⁻¹(3/4) + 2<em>nπ</em> <u>or</u> <em>x</em> = -cos⁻¹(3/4) + 2<em>nπ</em>
and from the second,
<em>x</em> = <em>nπ</em>
where <em>n</em> is any integer.
20% of 89.75 is 17.95

so :

the Trina's coupon will subtract the answer by 10%:
10%of 71.8 is 7.18

so the final answer is:

she has to pay $64.62
hope this helps