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
