3x - 1 = 3x + 1
subtract 3x from both sides to get (-1 = 1). This is a false statement so it is: CONTRADICTION
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4x - 11 = 7
add 11 to both sides and then divide both sides by 4 to get
. This statement is true only when x =
so it is: CONDITIONAL
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2 - 8x = 2 - 8x
add 8x to both sides to get (2 = 2). This is a true statement so it is: IDENTITY
*************************************************
x + 1 = -x + 4
add x to both sides, subtract 1 from both sides, and divide both sides by 2 to get
. This statement is true only when x =
so it is: CONDITIONAL
Answer: B, A, C, A
Answers:
- <u>24000 dollars</u> invested at 4%
- <u>18000 dollars</u> was invested at 7%
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Work Shown:
x = amount invested at 4%
If she invests x dollars at 4%, then the rest (42000-x) must be invested at the other rate of 7%
She earns 0.04x dollars from that first account and 0.07(42000-x) dollars from the second account
This means we have
0.04x+0.07(42000-x)
0.04x+0.07*42000-0.07x
0.04x+2940-0.07x
-0.03x+2940
This represents the total amount of money earned after 1 year.
We're told the amount earned in interest is $2220, so we can say,
-0.03x+2940 = 2220
-0.03x = 2220-2940
-0.03x = -720
x = -720/(-0.03)
x = 24000 dollars is the amount invested at 4%
42000-x = 42000-24000 = 18000 dollars was invested at 7%
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As a check, we can see that
18000+24000 = 42000
and also
0.04x = 0.04*24000 = 960 earned from the first account
0.07*18000 = 1260 earned from the second account
1260+960 = 2220 is the total interest earned from both accounts combined
This confirms our answers.
Answer:
b=8
Step-by-step explanation:
b=√(10²-6²)=√(100-36)=√64=8
Answer:
12600 (ZAR)
Step-by-step explanation:
4.2*3000