Answer:
math error ...............
I'm assuming the given function is f(x) = 15x^2 + 10x.
If so, then,
f(x) = 15x^2 + 10x
f(x) = 15*(x)^2 + 10*(x)
f(-1) = 15*(-1)^2 + 10*(-1) ... note how x is replaced with -1
f(-1) = 15*(1) + 10*(-1)
f(-1) = 15 - 10
f(-1) = 5
Therefore the answer is 5
Ratio of children, adults and pensioners is 1 : 2 : 8/3 = 3 : 6 : 8.
Let, 3x is number of children.
So, 6x is number of adults and 8x is number of pensioners.
Now,
3x + 6x + 8x = 85
17x = 85
x = 5
Therefore, number of pensioners are 8×5 = 40.
Hence, this is the required solution.
