What is the value of [tex]$x$[/tex] in the equation [tex]$3x - 4y = 65$[/tex], when [tex][tex]$y = 4$[/tex][/tex]?

A. [tex]x = 13 \frac{1}{4}[/tex]
B. [tex]x = 21 \frac{2}{3}[/tex]
C. [tex]x = 23[/tex]
D. [tex]x = 27[/tex]



Answer :

To determine the value of [tex]\( x \)[/tex] when [tex]\( y = 4 \)[/tex] in the equation [tex]\( 3x - 4y = 65 \)[/tex], let's follow these steps:

1. Substitute the given value of [tex]\( y \)[/tex] into the equation.
The equation given is:
[tex]\[ 3x - 4y = 65 \][/tex]
Substitute [tex]\( y = 4 \)[/tex]:
[tex]\[ 3x - 4(4) = 65 \][/tex]

2. Simplify the equation.
Calculate [tex]\( 4 \times 4 \)[/tex]:
[tex]\[ 4(4) = 16 \][/tex]
Now substitute back in:
[tex]\[ 3x - 16 = 65 \][/tex]

3. Isolate the term involving [tex]\( x \)[/tex].
To isolate [tex]\( 3x \)[/tex], add 16 to both sides of the equation:
[tex]\[ 3x - 16 + 16 = 65 + 16 \][/tex]
This simplifies to:
[tex]\[ 3x = 81 \][/tex]

4. Solve for [tex]\( x \)[/tex].
Divide both sides of the equation by 3:
[tex]\[ x = \frac{81}{3} \][/tex]
Simplify the right-hand side:
[tex]\[ x = 27 \][/tex]

Therefore, the value of [tex]\( x \)[/tex] when [tex]\( y = 4 \)[/tex] is [tex]\( \boxed{27} \)[/tex].