Question

what is the value of x in the equation 4x + 8y = 40, when y = 0.8?
4.6
8.4
10
12

Explanation:

Step1: Substitute y=0.8 into the equation

Substitute \( y = 0.8 \) into \( 4x + 8y = 40 \), we get \( 4x + 8\times0.8 = 40 \).

Step2: Simplify the equation

Calculate \( 8\times0.8 = 6.4 \), so the equation becomes \( 4x + 6.4 = 40 \).

Step3: Solve for x

Subtract 6.4 from both sides: \( 4x = 40 - 6.4 = 33.6 \). Then divide both sides by 4: \( x = \frac{33.6}{4} = 8.4 \).

Answer:

8.4