Question

Tolong ya bantu aku"please" pake cara...nomor 3 dan 4
.
yang nomor 3 itu soalnya 3x+4y=10 dan 4x-5y=34

Answer 1

Verified answer

Metode : Substitusi

3. 3x+4y = 10 dan 4x-5y = 34

3x+4y = 10
3x = 10-4y
x = 10/3-4/3y

4x-5y = 34
4(10/3-4/3y) -5y = 34
40/3 -16/3y -5y = 34
-16/3y-15/3y = 102/3-40/3
-31/3y = 62/3
-31y = 62
y = 62/-31
y = -2

3x+4y = 10
4y = 10-3x
y = 10/4-3/4x

4x-5y = 34
4x -5(10/4-3/4x) = 34
4x -50/4 + 15/4x = 34
16/4x+15/4x = 136/4+50/4
31/4x = 186/4
31x = 186
x = 186/31
x = 6

Metode : Campuran

3x+4y = 10 (dikali 4)
4x-5y = 34 (dikali 3)
------------------------
12x+16y = 40
12x-15y = 102
--------------(dikurang)
31y = -62
y = -62/31
y = -2

3x+4y = 10
3x+4(-2)= 10
3x-8 = 10
3x = 10+8
3x = 18
x = 18/3
x = 6