Question

What is the value of x in the equation 3x –1/2 y = 18, when y = 27?
answers given 5 7 45 63

Answer 1

For this case we have the following equation:

`3x- \frac {1} {2} y = 18`

We want to know the value of the variable x when
`y = 27`

For this, we substitute:

`3x- \frac {1} {2} 27 = 18\\3x = 18 + \frac {27} {2}\\3x = \frac {36 + 27} {2}\\3x = \frac {63} {2}\\x = \frac {63} {6}\\x = \frac {21} {2}`

Answer:

`x = \frac {21} {2}\ when\ y = 27`

Answer 2

10.5

Explanation:

Substitute 27 instead of y into the equation:

`3x-(1)/(2)\cdot 27=18.`

Then

`3x-13.5=18,\\ \\3x=18+13.5,\\ \\3x=31.5,\\ \\x=(31.5)/(3)=10.5.`