Let's find the value of [tex]\( y \)[/tex] in the given equation [tex]\( 6.4x + 2.8y = 44.4 \)[/tex] when [tex]\( x = 3 \)[/tex].
1. Substitute [tex]\( x = 3 \)[/tex] into the equation:
[tex]\[
6.4(3) + 2.8y = 44.4
\][/tex]
2. Calculate [tex]\( 6.4 \times 3 \)[/tex]:
[tex]\[
6.4 \times 3 = 19.2
\][/tex]
3. Replace [tex]\( 6.4 \times 3 \)[/tex] in the equation:
[tex]\[
19.2 + 2.8y = 44.4
\][/tex]
4. Isolate the term with [tex]\( y \)[/tex] by subtracting 19.2 from both sides:
[tex]\[
2.8y = 44.4 - 19.2
\][/tex]
5. Simplify the right-hand side:
[tex]\[
44.4 - 19.2 = 25.2
\][/tex]
6. So the equation becomes:
[tex]\[
2.8y = 25.2
\][/tex]
7. Solve for [tex]\( y \)[/tex] by dividing both sides by 2.8:
[tex]\[
y = \frac{25.2}{2.8}
\][/tex]
8. Perform the division:
[tex]\[
y = 9
\][/tex]
Therefore, the value of [tex]\( y \)[/tex] when [tex]\( x = 3 \)[/tex] is [tex]\( y = 9 \)[/tex].
So, the correct answer is [tex]\( y = 9 \)[/tex].
