Question

examples for substitution and elimination method

Answer 1

subsitution:
equation 1: x=1
equation 2: x + y = 2
substitute 1 in 2 
1 + y = 2
y = 2 - 1 (when 1 goes that side it becomes negative)
y = 1
elimination:
eq 1 : x + y -2 = 0
eq 2 : x - y - 4 = 0
if we eliminate y we get:
x -2 = 0
x - 4 = 0
add both,we get
2x -6 = 0
2x = 6
x = 3

Answer 2

Substitution:-

Step 1: 5x + 3y = 26              [Equation 1.]   
Step 2: x - 3y = 4                 [Equation 2.] 
Step 3: x = 3y + 4                 [Rearrange equation 2.]
Step 4: 5(3y + 4) + 3y = 26  [Substitute the values.]
Step 5: 18y + 20 = 26           [Group the like terms.] 
Step 6: 18y = 6      [Subtracting 20 from the two sides of the equation.] 
Step 7:        [Divide throughout by 18.]
Step 8:      [Substitute the values.]
Step 9: x = 5                            [Simplify.]
Step 10: The solution for the linear system is .