Question

Jika 4m -3n = 23 dan 3m + 2n = -4
TENTUKAN NILAI 7m -5n ?
(dalam Sistim persamaan linear dua variabel)

Answer 1

Cari m dan n
pake eliminasi dan substitusi ajaa
4m-3n=23
3m+2n=-4
hasilnya ntar dpt sendiriii

Answer 2

4m -3n = 23 (x3)
3m + 2n = -4 (x4) 

12m - 9n = 69
12m + 8n = -16 ⇔(dikurangi)

-17n = 85
n = 85/-17
n = -5

3m + 2n = -4
3m + 2(-5) = -4
3m - 10 = -4
3m = -4 + 10
3m = 6
m = 6/3
m = 2

7m - 5n = 7(2) - 5(-5) = 14 + 25 = 39