Question

2x-5y=15
3x+4y=11

maka nilai 2x+3y=

Answer 1

2x-5y=15 |x3 6x-15y=45
3x+4y=11 |x2 6x+8y=22
........................________ (-)
............................-23y=23
..................................y=-1

•2x-5y=15
2x-5(-1)=15
2x+5=15
2x=10
x=5

=2x+3y
=2(5)+3(-1)
=10-3
=7

Semiga membantu :)

Answer 2

Eliminasi
2x-5y=15 l x3   :6x-15y=45
3x+4y=11 l x2   :6x+8y=22
                          _________ -
                              -7y=23
                                 y=-23/7
subtitusi
2x-5y=15
2x-5(-23/7)=15
2x+(115/7)=15
2x=15-(115/7)
2x=(105-115)/7
2x=-10/7
x=(-10/7)/2
x=(-10/7)*(1/2)
x=-5/7
nilai 2x+3y=2(-5/7)+3(-23/7)=(-10/7)-(63/7)=(-73/7)