Question

which of these shows the result of using the first equation to substitute for y in the second equation, then combining like terms ?
y=3x
3x+2y=18
A. 3y=18
B.3x=18
C. 9x=18
d. 6x=18

Answer 1

Answer:

step-by-step explanation:answer is c

y=3x

3x+2(3x)=18

3x+6x=18

9x=18

or

x=3

y=3(3)

y=9

Answer 2

Answer: - C. 9x = 18.

Detailed solution: -

Given: -

The two-equation y = 3x and 3x + 2y = 18 are given.

We need to find that from the given options which option shows the result of using the first equation to substitute for y in the second equation given, then combining the like terms for the given equation.

Therefore,

The correct answer is option C. 9x + 18.

The value of y = 3x

Putting the value of y = 3x in the equation 3x + 12y = 18, we get,

3x + 12 y = 18

$3x+2*3x=18\\3x+6x=18$

9x = 18

Therefore,

Now we can find the value of x.

$x=18/9\\x=2$

The value of x = 2.

Now,

By putting the value of x = 2 in the equation y = 3x, we can find the value of y.

$y=3*2$

y = 6

The value of y = 6.

Therefore,

By seeing the solution, you can see that the 9x = 18 is the result of using the first equation in the second equation as the value of y and then we get the values of both x and y.

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https://brainly.in/question/54148168

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