Answer:
Solution point is (-1,-9)
Step-by-step explanation:
Put the value of y in the first equation into the second equation.
- 2x + 5(3x - 5) = - 42 Remove the brackets on the left
- 2x + 15x - 25 = - 42 Combine like terms on the left
- 17x - 25 = - 42 Add 25 to both sides
- 17x - 25 + 25 = - 42 + 25 Do the addition
- 17x = - 17 Divide by 17
- 17x/17 = -17/17 Do the division
- x = - 1
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Solve for y
- y = 3x - 6
- x = -1
- y = 3(-1) - 6
- y = -3 - 6
- y = - 9
Y/3=12 should be y=63 because 63/3=12
Let a, b, and c be the times each pump will fill the tank when working alone.
Therefore, in 1 hour;
1/a +1/b = 1/(6/5) = 5/6 ---- (1)
1/a+1/c = 1/(3/2) = 2/3 ---- (2)
1/b+1/c = 1/(2) = 1/2 ---- (3)
From equation (1)
1/a = 5/6-1/b
Substituting for 1/a in eqn (2)
5/6-1/b+1/c = 2/3
-1/b +1/c = -1/6 => 1/c = 1/b - 1/6 --- (4)
Using eqn (4) in eqn (3)
1/b+1/b-1/6 = 1/2
2/b-1/6 = 1/2
2/b =1/2+1/6 = 2/3
1/b = 1/3
Then,
1/c = 1/3 - 1/6 = 1/6
1/a = 5/6 - 1/3 = 1/2
This means, in 1 hour and with all the pumps working together, the tank will be filled to;
1/a+1/b+1/c = 1/2+1/3+1/6 = 1 (filled fully).
Therefore, it will take 1 hour to fill the tank when all pumps are working together.
50.24
4 squared is 16
16•3.14= 50.24
A= 3.14(4)^2
:)
