Step-by-step explanation:
You can solve systems of equations using either substitution or elimination. For these problems, I recommend elimination. I'll do the first one as an example.
-3x + 16y = 9
-4x + 8y = 12
Multiply the second equation by -2.
8x − 16y = -24
Add to the first equation (notice the y's cancel out).
(-3x + 16y) + (8x − 16y) = 9 − 24
5x = -15
Solve for x.
x = -3
Now you can plug this into either equation to find y.
-3(-3) + 16y = 9
9 + 16y = 9
y = 0
The solution is (-3, 0).
Answer:
Explanation
Step-by-step explanation:
Angles 2 and 6 are corresponding angles in a transversal meaning they have the same measure.
9514 1404 393
Answer:
a) average rate = (total distance)/(total time)
b) Rave = 2·R1·R2/(R1 +R2)
c) cheetah's average rate ≈ 50.91 mph
Step-by-step explanation:
a) Let AB represent the distance from A to B. Let t1 and t2 represent the travel times (in hours) on leg1 and leg2 of the trip, respectively. Then the distances traveled are...
First leg distance: AB = 70·t1 ⇒ t1 = AB/70
Second leg distance: AB = 40·t2 ⇒ t2 = AB/40
The average rate is the ratio of total distance to total time:
average rate = (AB +AB)/(t1 +t2)
average rate = 2AB/(AB/70 +AB/40) = 2/(1/70 +1/40) = 2(40)(70)/(70+40)
average rate = 560/11 = 50 10/11 . . . mph
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No equations are given, so we cannot compare what we wrote with the given equations. In each step of the solution, we have used the rules of algebra and equality.
b) For two rates over the same distance (as above), the average is their harmonic mean:
average rate = 2r1·r2/(r1+r2)
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c) The cheetah's average rate was 50 10/11 mph ≈ 50.91 mph.
Answer:
y + 11 = 14
Step-by-step explanation:
If Bobby claims Peter started with 21 cards, then we'll work this into our equation.
21 - 3 (that he lost) = 18
18 / 2 (the half he gave) = 9
So this means that he did have 21 cards to begin with. Please reply to this with a list of the answers that can/could be checked!
