The answer is actually choice A
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If we add up the equations straight down we will have 0a+2b = 6
Note how adding the 'a' terms gives us 3a + (-3a) = 3a-3a = 0a. The 0a term is really 0 since 0 times anything is 0. So the 'a' terms will go away
The equation 0a+2b = 6 turns into 0+2b = 6 and that simplifies to 2b = 6
To isolate b, we divide both sides by 2
2b = 6
2b/2 = 6/2
b = 3
We can stop here since only one answer choice has b = 3, which is choice A. However, let's keep going to find the value of 'a'
Plug b = 3 into any equation with 'a' and 'b', then solve for 'a'
3a+4b = 9
3a+4*3 = 9
3a+12 = 9
3a+12-12 = 9-12
3a = -3
3a/3 = -3/3
a = -1
So a = -1 and b = 3 pair up to form (a,b) = (-1,3)
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To check, plug this ordered pair back into both equations
Equation 1:
3a+4b = 9
3*(-1)+4*3 = 9
-3+12 = 9
9 = 9
Equation 1 has been checked out
Equation 2:
-3a-2b = -3
-3(-1)-2(3) = -3
3 - 6 = -3
-3 = -3
this is true as well
So this confirms that the final answer is choice A
I'm not quite sure these are right. You might wanna check with a classmate or something first.
Step-by-step explanation:
(6x + 10) + (x + 17) + (4x - 34) = 180
11x - 7 = 180
11x = 173
x = 15.73 (answer had repeating decimal so i rounded up in the hundredths place)
(6x + 10)
6 (15.73) + 10
94.38 + 10
104.38
(x + 17)
(15.73) + 17
32.73
(4x - 34)
4(15.73) - 34
62.92 - 34
28.92
9514 1404 393
Answer:
50 m/s
Step-by-step explanation:
Ian's rate was ...
(180,000 m)/(3600 s) = 50 m/s
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There are 1000 meters in a kilometer, and there are 3600 seconds in 1 hour. To find meters per second, divide meters by seconds.
