Matematika

Pertanyaan

X + y =9
2y + 3z =7
X - 2z =4

Maka nilai dari (x-y+z) adalah....

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  • Materi : SPLTV

    x + y = 9 ...............1)
    2y + 3z = 7 .......... 2)
    x - 2z = 4 ............. 3)

    x + y = 9 ........ ×2
    2y + 3z = 7 ..... ×1
    --------------------------
    2x + 2y = 18
    3z + 2y = 7
    -------------------------(-)
    2x - 3z = 11 ................ 4)

    2x - 3z = 11 ...... ×1
    x - 2z = 4 .......... ×2
    ---------------------------
    2x - 3z = 11
    2x - 4z = 8
    ---------------------------(-)
    z = 3


    2x - 3z = 11
    2x - 3(3) = 11
    2x - 9 = 11
    2x = 11 + 9
    2x = 20
    x = 10

    x + y = 9
    10 + y = 9
    y = 9 - 10
    y = -1

    Hp = { 10 , -1 , 3 }

    Jadi , Nilai x - y + z
    ⇒ 10 - (-1) + 3
    ⇒ 10 + 1 + 3
    ⇒ 11 + 3
    ⇒ 14


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