Question

Point M is the midpoint of CD. What is the value of a in the figure?

Answer 1

Answer:

a=3

Step-by-step explanation:

Given points (a, b) and (c,d), the midpoint of the points will be at

((a+c)/2, ((b+d)/2)

Therefore, given (9, 2) and (a,2a), our midpoint is at

((9+a)/2, (2+2a)/2) = (6,4)

Matching the x values to their corresponding x values and doing the same with the y values, we get

(9+a)/2 = 6

(2+2a)/2 = 4

First, we have

(9+a)/2 = 6

multiply both sides by 2 to remove the denominator

9+a = 12

subtract 9 from both sides to isolate a

a = 3

2a = 2 * a = 6

Confirming this, we have

(2+2a)/2 = 4

(2+6)/2 = 4

8/2=4