Two equations that have the same solution are called equivalent equations e.g. 5 +3 = 2 + 6. And this as we learned in a previous section is shown by the equality sign =. An inverse operation are two operations that undo each other e.g. addition and subtraction or multiplication and division. You can perform the same inverse operation on each side of an equivalent equation without changing the equality.
Answer:
x = 3, y = - 1, z = 1
Step-by-step explanation:
listing the coefficients
1 - 2 1 6 ← R1
3 1 - 1 7 ← R2
4 - 1 2 15 ← R3
We require the first entry in R2 to be 0 while retaining R1 and the first 2 entries of R3 to be 0, thus
R2 - 3R1 and R3 - 4R1
1 - 2 1 6 ← R1
0 7 - 4 - 11 ← R2
0 7 - 2 - 9 ← R3
Now R3 - R2
1 - 2 1 6 ← R1
0 7 - 4 - 11 ← R2
0 0 2 2 ← R3
From R3
2z = 2 ⇒ z = 1
Substitute z = 1 into R2
7y - 4(1) = - 11
7y - 4 = - 11 ( add 4 to both sides )
7y = - 7 ⇒ y = - 1
Substitute y = - 1, x = 1 into R1
x - 2(- 1) + 1 = 6
x + 2 + 1 = 6
x + 3 = 6 ( subtract 3 from both sides )
x = 3
Solution is (3, - 1, 1 )
A means x
b means y
so (-,+) is <span>quadrant II</span>
answer is <span>B)
II. </span>
Answer:
the answer is 2x
Step-by-step explanation: