garis dengan persamaan ax+by=7 melalui titik (3,-2) dan (2,1) nilai a + b

Bab Persamaan Garis
Matematika SMP Kelas VIII

(3, -2)
3a - 2b = 7

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(2, 1)
2a + b = 7
b = -2a + 7

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3a - 2b = 7
3a - 2 (-2a + 7) = 7
3a + 4a - 14 = 7
7a = 7 + 14
a = 21/7
a = 3

b = -2a + 7
b = -2 . 3 + 7
b = -6 + 7
b = 1

a + b
= 3 + 1
= 4