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X + 9y + z = 20

x + 10y – 2z = 18
3x + 27y + 2z = 58
A. (4, 2, 6)
B. (2, 4, 6)
C. (6, 4, 2)
D. (6, 2, 4)

User Moid
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1 Answer

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Final answer:

To solve the system of equations x + 9y + z = 20, x + 10y – 2z = 18, and 3x + 27y + 2z = 58, we can use the substitution method. First, we can solve for x in terms of y and z in one of the equations and substitute it into the other equations. By simplifying and solving the resulting equations, we find that the values of x, y, and z are -18, 4, and 2, respectively.

Step-by-step explanation:

To solve the system of equations:

x + 9y + z = 20

x + 10y – 2z = 18

3x + 27y + 2z = 58

We can use the method of elimination or substitution. Let's use the substitution method:

From the first equation, we can rewrite it as x = 20 - 9y - z.

Substituting this value of x into the second equation, we get:

(20 - 9y - z) + 10y - 2z = 18.

Simplifying this equation, we get 10 - y - 3z = 18.

From the third equation, we can rewrite it as x = (58 - 27y - 2z) / 3.

Substituting this value of x into the first equation, we get:

(58 - 27y - 2z) / 3 + 9y + z = 20.

Simplifying this equation, we get 58 - 27y - 2z + 27y + 3z = 60.

Combining like terms, we get z = 2.

Substituting this value of z into the second equation, we get:

x + 10y - 2(2) = 18.

Simplifying this equation, we get x + 10y - 4 = 18.

Combining like terms, we get x + 10y = 22.

Substituting the value of x from the first equation, we get:

(20 - 9y - 2) + 10y = 22.

Simplifying this equation, we get 20 - 9y - 2 + 10y = 22.

Combining like terms, we get y = 4.

Finally, substituting the values of x and y into the first equation, we get:

20 - 9(4) - 2 = 20 - 36 - 2 = -18.

Therefore, the solution to the system of equations is x = -18, y = 4, and z = 2.

User Glenc
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