We are given the equations 3x+5y=-3 and x-5y=-5.
Both equations have a 5y term which allows us to easily solve the system by elimination. To do so we will add the equations together like a simple addition problem by adding the x terms together, the y terms together, and the integer answers together.
3x + 5y = -3
+x - 5y = -5
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4x + 0y = -8
The y terms cancel out since one is positive and one is negative. Now we can solve for x.
4x = -8

x = -2
Now plug -2 in for x in one of the original equations to find y.
(-2) - 5y = -5
-5y = -3
y = 3/5
Our answer as an ordered pair is (2, 3/5)
Thirty three because I'm just smart like that so you should believe me entirely.
Answer:
(-6127) + 0 = (-6127)
(+18) + 2 = (+20)
(+27) - 7 = (+20)
(+63) + (-13) = (+50)
(+21) - 4 = (+17)
Step-by-step explanation:
9514 1404 393
Answer:
(c) (3, 3)
Step-by-step explanation:
Point E partitions both the x-distance and the y-distance in the ratio 2 : 1. That is, for either the x-coordinates or the y-coordinates, ...
CE : ED = 2 : 1
Try the answers with the x-coordinates.
CE : ED = (1 -(-1)) : (5 - 1) = 2 : 4 . . . . incorrect
CE : ED = (-3 -(-1)) : (5 -(-3)) = -2 : 8 . . . . incorrect
CE : ED = (3 -(-1)) : (5 -3) = 4 : 2 = 2 : 1 . . . . correct
CE : ED = (-1 -(-1)) : (5 -(-1)) = 0 : 6 . . . . incorrect
The only viable choice is (3, 3).
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<em>Alternate solution</em>
For a partitioning of m : n, the desired point is ...
E = (n×C +m×D)/(m+n)
For partitioning of 2 : 1, the desired point is ...
E = (1×(-1, -3) + 2×(5, 6))/(2+1) = (-1+10, -3 +12)/3
E = (3, 3)
Answer:
A(t) = 300 -260e^(-t/50)
Step-by-step explanation:
The rate of change of A(t) is ...
A'(t) = 6 -6/300·A(t)
Rewriting, we have ...
A'(t) +(1/50)A(t) = 6
This has solution ...
A(t) = p + qe^-(t/50)
We need to find the values of p and q. Using the differential equation, we ahve ...
A'(t) = -q/50e^-(t/50) = 6 - (p +qe^-(t/50))/50
0 = 6 -p/50
p = 300
From the initial condition, ...
A(0) = 300 +q = 40
q = -260
So, the complete solution is ...
A(t) = 300 -260e^(-t/50)
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The salt in the tank increases in exponentially decaying fashion from 40 grams to 300 grams with a time constant of 50 minutes.