Question

Tolong bantu ya teman.. nomor 12 yaa .

Answer 1

A.)
diketahui :
x = 1
y = 2

maka :
9x + by = 1
9(1) + 2b = 1
9 + 2b = 1
2b = 1 - 9
2b = -8
b = -8/2
b = -4

b.)
diketahui :
x = 2
y = -2

maka :
(b + 1)x + 7y = -8
(b + 1)2 + 7(-2) = -8
2b + 2 - 14 = -8
2b - 12 = -8
2b = -8 + 12
2b = 4
b = 4/2
b = 2

c.)
diketahui :
x = b
y = 4

maka :
2x - by = -10
2b - 4b = -10
-2b = -10
b = -10/-2
b = 5

Semoga membantu :)

Answer 2

A.)
 9x + by = 1
9(1) + 2b = 1
9 + 2b = 1
 2b = 1 - 9
2b = -8
b = -8/2
b = -4

b.)  (b + 1)x + 7y = -8
(b + 1)2 + 7(-2) = -8
 2b + 2 - 14 = -8
2b - 12 = -8
2b = -8 + 12
2b = 4
b = 4/2
b = 2

c.)  2x - by = -10
2b - 4b = -10
-2b = -10
b = -10/-2
b = 5