Matematika

Pertanyaan

Tolong ya kak
Tidak harus semuanya 5 aja cukup
Terima kasih.....
Tolong ya kak Tidak harus semuanya 5 aja cukup Terima kasih.....

2 Jawaban

  • 1)
    -3x + 9 = 5y + 3
    -3x - 5y = 3 - 9
    -3x - 5y = -6

    m = -a/b
    m = -(-3)/(-5)
    m = -3/5

    gradien = -3/5

    2)
    melalui titik (2, -5) dan (4, 6)
    m = (y2 - y1) / (x2 - x1)
    m = (6 - (-5)) / (4 - 2)
    m = 11/2

    3)
    gradien garis yang melalui titik (5, 2) dan (-5, -3)
    m = (y2 - y1) / (x2 - x1)
    m = (-3 - 2) / (-5 - 5)
    m = (-5) / (-10)
    m = 1/2

    syarat tegak lurus
    m1.m2 = -1
    1/2 . m2 = -1
    m2 = -2

    Persamaan garis melalui titik (-3, 2)
    (y - y1) = m(x - 1)
    (y - 2) = -2(x - (-3))
    y - 2 = -2x - 6
    y = -2x - 6 + 2
    y = -2x - 4

    4)
    P(a, 2)
    x = a
    y = 2

    3x - 7y = -26
    3a - 7(2) = -26
    3a - 14 = -26
    3a = -26 + 14
    3a = -12
    a = -4

    Q(3, b)
    x = 3
    y = b

    3x - 7y = -26
    3(3) - 7b = -26
    9 - 7b = -26
    -7b = -26 - 9
    -7b = -35
    b = 5

    a + b = -4 + 5 = 1

    5)
    titik potong
    y = -x + 2
    y = x - 1

    -x + 2 = x - 1
    -x - x = -1 - 2
    -2x = -3
    x = 3/2

    y = x - 1
    y = 3/2 - 1
    y = 1/2

    titik potong (3/2 , 1/2)


  • Bab Persamaan Garis
    Matematika SMP Kelas VIII

    1] -3x + 9 = 5y + 3
    5y = -3x + 9 - 3
    y = (-3/5) x + (6/5)

    gradien = m = -3/5

    2] m = (y2 - y1) / (x2 - x1)
    m = (6 + 5) / (4 - 2)
    m = 11/2

    5] y = y
        -x + 2 = x - 2
        -x - x = -2 - 2
        -2x = -4
        x = -4 : (-2)
        x = 2

        y = x - 2
          = 2 - 2
          = 0

    (2, 0)

    7] 3x + 2y = 4, tegak lurus, (2, -1)
        2x - 3y = 2 . 2 - 3 . (-1)  
        2x - 3y = 4 + 3
        2x - 3y = 7

    8] (y - y1) / (y2 - y1) = (x - x1) / (x2 - x1)
        (y - 0) / (4 - 0) = (x - 0) / (-2 - 0)
        y / (-2) = 4x
        y = -8x

    9] 2x + 3y = 15
        2 . (-a) + 3 . 3 = 15
       -2a + 9 = 15
       -2a = 15 - 9
        a = 6 : (-2)
        a = -3