9x+ 12ⅹ=2 1
Solution:
(9+ 12)x=2 1
2 1x=2 1
x= 1
So 9x+ 12 x = 2 1 The final result of solving the equation is x= 1.
Extended data:
Two solutions of binary linear equation;
1, addition, subtraction and elimination
Example: Solve the system of equations x+y=9① x-y=5②.
Solution: ①+②, 2x= 14, that is, x=7.
Bring x=7 into ① to get 7+y=9 and y=2.
∴x=7,y=2
2. Substitution elimination
Example: Solve the system of equations x+y = 5 16x+ 13y = 89②.
Solution: Take ③ from ① with x=5-y③ to ② to get 6(5-y)+ 13y=89 and y=59/7.
Bring y=59/7 into ③ to get x=5-59/7, that is, x=-24/7.
∴x=-24/7,y=59/7
Elimination method: the unknowns in the equation are solved one by one from more to less.