Question

Y=2x dan x+3y=-21 ,cara substitusi,garap pake caranya

Answer 1

X+3y=-21
x+3(2×)=-21
×+6×=-21
7×=-21
×=-3

Answer 2

Y = 2x
x +3y = -21
x + 3 ( 2x) = -21
x + 6x = -21
7x = -21
x = -21 : 7
x = -3 

x + 3y = -21
-3 + 3y = -21
3y = -21 + 3
3y = -18
y = -18 : 2
y = - 9
jadi, X = -3 dan Y = -9

Maaf kalau salah ..