Respuesta :
8x +7y = 39 multiply everything by 2
2(8x +7y = 39)
16x +14y = 78
+4x - 14y= -68
-------------------------
20x = 10
20x /20 = 10/20
x = 1/2
Plug x into first formula
8 x + 7y =39
8(1/2) 7y=39
4+ 7y =39
4-4+7y =39-4
7y =35
7y/7 = 35/7
y = 5
(1/2, 5)
2(8x +7y = 39)
16x +14y = 78
+4x - 14y= -68
-------------------------
20x = 10
20x /20 = 10/20
x = 1/2
Plug x into first formula
8 x + 7y =39
8(1/2) 7y=39
4+ 7y =39
4-4+7y =39-4
7y =35
7y/7 = 35/7
y = 5
(1/2, 5)
The given system of linear equations has a unique solution. The solution to the system of equations is [tex](\frac{1}{2}, 5)[/tex].
Given equations:
[tex]8x+7y=39[/tex] ...........(i)
[tex]4x-14y=-68[/tex] ...........(ii)
Multiply the first equation by 2 to enable the elimination of the y-term.
[tex]2(8x+7y=39)\\16x+14y=78[/tex] ...........(iii)
Add the equations (ii) and (iii) to eliminate the y-terms
[tex]4x-14y=-68\\16x+14y=78[/tex]
------------------------------
[tex]20x=10[/tex]
or [tex]x=\frac{10}{20}[/tex]
or [tex]x=\frac{1}{2}[/tex]
Plug x into equation (i) to find the x-value
[tex]8(\frac{1}{2}) +7y=39\\4+7y=39\\7y=39-4\\7y=35\\y=\frac{35}{7} \\y=5[/tex]
Check the solution
[tex]8x+7y=39[/tex]
For
[tex]x=\frac{1}{2} \\y=5[/tex]
[tex]8(\frac{1}{2} )+7(5)=39\\4+35=39\\39=39[/tex]
LHS = RHS
Therefore, the solution to the system of equations is [tex](\frac{1}{2} , 5)[/tex].
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