Explanation:
To find the value of x in the equation 4x + 8y = 40, when y = 0.8, we can substitute the value of y into the equation and solve for x.
Substituting y = 0.8 into the equation, we have:
4x + 8(0.8) = 40
Simplifying the equation, we get:
4x + 6.4 = 40
To isolate x, we need to move 6.4 to the other side of the equation by subtracting it from both sides:
4x = 40 - 6.4
4x = 33.6
Finally, we can solve for x by dividing both sides of the equation by 4:
x = 33.6 / 4
x = 8.4
Therefore, the value of x in the equation 4x + 8y = 40, when y = 0.8, is x = 8.4.
Now, let's move on to the solution of the equation. The equation 4x + 8y = 40 represents a linear relationship between x and y. We can interpret this equation as follows: for every increase of 1 in x, the value of y increases by 2. In other words, the coefficient of x (4) represents the rate of change of y with respect to x.
To find the solution of the equation, we can plot the equation on a graph and find the point where the line intersects the y-axis. This point represents the value of y when x is equal to 0. In this case, when x = 0, the equation becomes:
4(0) + 8y = 40
8y = 40
Dividing both sides by 8, we get:
y = 5
Therefore, the solution of the equation is (0, 5), which means that when x = 0, y = 5.