Question

Himpunan penyelesaian
6/x + 3/y = 21
7/x - 4/y = 2
adalah {(x0, y0)}. nilai dari 6x0. y0 = ....
a. 1/6
b. 1/5
c. 1
d. 6
e. 36

Answer 1

Persamaan 2 Variabel

6/x+3/y=21
7/x-4/y=2
---------------

6(y)+3(x)/(xy)=21
7(y)-4(x)/(xy)=2

6y+3x/(xy)=21
7y-4x/(xy)=2

3x+6y=21xy
-4x+7y=2xy

12x+24y=84xy
-12x+21y= 6xy
------------------- (+)
45y=90xy
45y/90y=x
45/90=x
5/10=x
1/2=x

12x+24y=84xy
12(1/2)+24y=84(1/2)y
6+24y=42y
6=42y-24y
6=18y
6/18=y
1/3=y

6x.y=6(1/2).(1/3)
=6(1/6)
=1
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Pilihan C.

Demikian Semoga Membantu dan Bermanfaat!