Addition, subtraction and elimination method is suitable for solving the equation with the same unknown coefficient as integer multiple, such as
x
+
y
=
nine
................& lt 1 & gt;
x
-
2y
=
-3..............& lt2 & gt
& lt 1 & gt;
-
& lt 1 & gt; get
3y
=
12
y
=
four
X can be obtained simply by substitution.
=
five
3x
-
y
=
1..........................& lt 1 & gt;
2x
+
3y
=
8.....................,.& lt2 & gt
Observation shows that the coefficient of y is three times, so
3×& lt; 1 & gt;
+
& lt2> gets
1 1x
=
1 1
x
=
1
Then y is obtained by substitution method.
=
2