Certainly! Let's solve the problem step-by-step.
Given the equation [tex]\( 4x + 8y = 40 \)[/tex] and the value [tex]\( y = 0.8 \)[/tex], we need to determine the value of [tex]\( x \)[/tex].
1. Substitute the given value [tex]\( y = 0.8 \)[/tex] into the equation:
[tex]\[
4x + 8(0.8) = 40
\][/tex]
2. Simplify the equation by calculating [tex]\( 8 \times 0.8 \)[/tex]:
[tex]\[
8(0.8) = 6.4
\][/tex]
So the equation becomes:
[tex]\[
4x + 6.4 = 40
\][/tex]
3. Isolate the term involving [tex]\( x \)[/tex] by subtracting 6.4 from both sides of the equation:
[tex]\[
4x + 6.4 - 6.4 = 40 - 6.4
\][/tex]
[tex]\[
4x = 33.6
\][/tex]
4. Solve for [tex]\( x \)[/tex] by dividing both sides of the equation by 4:
[tex]\[
x = \frac{33.6}{4}
\][/tex]
[tex]\[
x = 8.4
\][/tex]
Therefore, the value of [tex]\( x \)[/tex] is 8.4.
The correct choice is:
[tex]\[
\boxed{8.4}
\][/tex]
