Answer:
15.
Step-by-step explanation:
Let his age now be x years. Then:
(x - 3)^2 = 6(x + 9)
x^2 - 6x + 9 = 6x + 54
x^2 - 12x - 45 = 0
(x - 15)(x + 3) = 0
x = 15, -3
We ignore the negative so his age now is 15.
Age= 15
Let a be for age at the moment
(a-3)^2 =6(a+9)
a^2-6a+9=6a+54
a^2-12a-45
(a-15)(a+3)
a=15 or a=-3
Age cannot be negative (-)
Therefore
Age =15
y > -x + 3
find the slope and y-intercept so you can create a linear equation:
y = mx + b ; m = slope and b = y-intercept
slope (m) = (3-0) / (0-3)
m = 3/-3 or -1
we can see the y-intercept by looking at the graph, it is 3
