what is the value of y in the equation 6.4x + 2.8y = 44.4, when x = 3?\no y = 5\no y = 6\no y = 8\no y = 9

Explanation:

Step1: Substitute x value

Substitute (x = 3) into the equation (6.4x+2.8y = 44.4). We get (6.4\times3+2.8y=44.4). [6.4\times3+2.8y = 44.4] [19.2+2.8y=44.4]

Step2: Isolate the term with y

Subtract 19.2 from both sides of the equation: (2.8y=44.4 - 19.2). [2.8y=44.4 - 19.2] [2.8y = 25.2]

Step3: Solve for y

Divide both sides of the equation by 2.8: (y=\frac{25.2}{2.8}). [y=\frac{25.2}{2.8}=9]

Answer:

D. (y = 9)