It's 18 it means 18 times 3 becomes 54 and that's how you get it
See attachment
then we add 7 and 5 and divide that by 2, which gives you
6 (x-coordinate)
and add 10 and -8 and divide that by 2, which gives you
1 (y-coordinate)the answer is (6, 1)justification
so midpoint is basically the middle point of 2 points
that's why we have to add the two x coordinates first then divide it by 2
or add the two y coordinates then divide it by 2
The equation of the line is : y +2x = 1
Answer:

Step-by-step explanation:

Let x = John's age now
half of what johns age was 4 years ago: (1/2)(x-4)
is equal to one third of what it will be in 5 years time: (1/3)(x+5)
(1/2)(x-4) = (1/3)(x+5)
3(x-4) = 2(x+5)
3x - 12 = 2x + 10