12 Answers
- Engr. RonaldLv 71 month ago
3x - 5y = 60 .. eq1
4x + 5y = - 4 .. eq2
---------------------
7x = 56
x = 8 answer//
plug in x = 8 to eq1
3x - 5y = 60
3(8) - 5y = 60
24 - 5y = 60
- 5y = 60 - 24
- 5y = 36
y = - 36/5 answer//
- PhilomelLv 71 month ago
3x-5y=60
4x+5y=- 4
add
7x=56>>>x=8
24-5y=36>>>y= - 36/5
32+5y= - 4
5y= - 4- 32=-36>>y= - 36/5 ok
- 1 month ago
3x - 5y = 60 -------------1
4x + 5y = - 4--------------2
Adding the above equations, we get
7x = 56
or x = 8
Equation 2 is 4x + 5y = - 4
So,
5y = - 4 – 32
y = -7.2
- PuzzlingLv 71 month ago
You can just type this system into WolframAlpha and get the answer.
Or you could do it yourself. Given that you have -5y and 5y, you can add the equations and eliminate y as a variable. That leaves:
7x = 56
x = 56/7
x = 8
Then plug that into either equation to get y.
Answer:
x = 8
y = -36/5 (or -7.2)
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- la consoleLv 71 month ago
(1) : 3x - 5y = 60
(2) : 4x + 5y = - 4
You calculate (1) + (2):
(3x - 5y) + (4x + 5y) = 60 + (- 4)
3x - 5y + 4x + 5y = 60 - 4
7x = 56
x = 8
Recall (1):
3x - 5y = 60
24 - 5y = 60
5y = 24 - 60
5y = - 36
y = - 36/5
- az_lenderLv 71 month ago
Add the two equations, you get 7x = 56, so x = 8,
and then 24 - 5y = 60, so 5y = -36 and y = -7.2
- 1 month ago
add two equation 3x-5y+4x+5y=60-4
7x=56
x=56/7
x=8
put the value on equation 1
3*8-5y=60
24-5y=60
-5y=36
y=-36/5