2x+3y=11 x+4y=8 nilai dari 3x-8y=

2x+3y=11
x+4y=8

nilai 3x-8y=

2x+3y=11 | x1
x+4y=8. | x2
___________

2x+3y=11 >>> pers (1)
2x+8y=16>>> pers (2)
________ -

-5y=-5
[y=1]

substitusi ke pers (1) atau (2)
2x+3y =11
2x+3(1)=11
2x+3=11
2x=11-3
2x=8
[x=4]


soalnya>> 3x-8y =
3(4)-8(1)= 12-8
=??? saya tidak tahu

2x + 3y = 11 [1]
x + 4y = 8 [2]

Persamaan [2] dan [1]

x + 4y = 8 | dikalikan 2
2x + 3y = 11 | dikalikan 1

2x + 8y = 16
2x + 3y = 11
——————— [-]
5y = 5
y = 5/5
y = 1

Substitusi [2]

x + 4y = 8
x + 4(1) = 8
x + 4 = 8
x = 8 - 4
x = 4

HP = {x, y} = {4, 1}

Jadi, 3x - 8y = ..... ?

3x - 8y = ..... ?
3(4) - 8(1) = ..... ?
12 - 8 = 4

Jadi, hasil dari 3x - 8y = 4

Semoga membantu :)