The given function as;
f(x) = x² - 8x + 3
f(x + h) , susbtitute x = x + h in the given expression as;
f(x+h) = (x+h)² - 8(x+h) + 3
f(x+h) = (x² + h² + 2xh) -8x - 8h + 3
f(x+h) = x² + h² + 2xh - 8x - 8h + 3
Now substitute the value of f(x+h) in the expression as;
Answer : 2x + h - 8
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