I assume the first equation is supposed to be
and not
As an augmented matrix, this system is given by
Multiply through row 3 by 1/2:
Add -1(row 2) to row 3:
Multiply through row 3 by 1/5:
Add -2(row 3) to row 1, and add 3(row 3) to row 2:
Add -3(row 2) to row 1:
Multiply through row 1 by -1:
Add -2(row 1) to row 2:
Multipy through row 2 by -1:
The solution to the system is then
Answer:The first method, by substituting 5 into the expression (-2)x + 6 gives the coreect answer of -4
Step-by-step explanation:
Ist method
Substituting x = 5 into the expression (-2)x + 6, we have
(-2) 5 + 6,
=-10 + 6
=-4
2nd method
Substitute x = -1 into the expression (-2)x + 6,we have
(-2)(-1) + 6
2 +6=10
The first method, by substituting 5 into the expression (-2)x + 6 gives the coreect answer of -4