Answer:
speed = distance/ time so:
(2/7) / (2/5) = (2/7) x (5/2) = 10/14 = 5/7 mph
5/7 = 0.71 miles per hour if you need decimal formatStep-by-step explanation:
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
Answer:
Step-by-step explanatiion:
-8/3=-2.67
Number less -2.7 are
-2.8; -2.9; -3.0; and so on
As there is 5 more girls than boys and b is the number of boys, the expression b + 5 represents the number of girls.
total there are 27 childrens
b + (b+5) = 27
b + b + 5 = 27
2b = 27 -5
b =22 / 2
b =11
so the number of boys there are 11 and girls are 11 + 5 = 16
and total is 16 + 11 = 27
Answer:
4) 5
Step-by-step explanation:
3x-x+2=12
First, you combine similar terms, so 3x-x which is 2x.
Second, you subtract 2 on both sides which is going to give you 2x=10.
Finally, you divide by 2 on both sides, so the final answer is going to be x=5.
