Question

Diketahui x dan y merupakan penyelesaian sistem persamaan x + 2y = 7 dan y = 3x + 7. nilai x²y adalah......

Answer 1

X + 2y = 7
x = 7 - 2y

y= 3x + 7
y = 3(7-2y) +7
y = 21-6y+7
y = 28-6y
y+6y = 28
7y = 28
y = 28/ 7 = 4

y= 3x + 7
4 = 3x+ 7
4-7 = 3x
-3 = 3x
x = -1

xy = 1x4= 4

Answer 2

X + 2y = 7
-1 + 2.4 = 7
-1 + 8 = 7

y = 3x + 7
4 = (-1).3 + 7
4 = -3 +7
x²y = (-1)².4
=1.4
=4 

Maaf Kalo Salah :)