You add 13 and 8 it gets 21 so for X its 13
<span> f (x)= 10-x³.
f(2) means the value of the function when x=2.
So, we need to substitute 2 instead of x.
f(2) = 10 - 2³ = 10-8 =2
f(2) = 2
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I cant help you there m8 the I'm not able to see the problem I'm sorry.