Question 1120615
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905 would be the answer if the function were defined as f(x) = 4x^2+5:<br>
f(15) = 4(15^2)+5 = 4(225)+5 = 900+5 = 905<br>
But the function is defined as f(4x-1) = 4x^2+5.  To evaluate f(15), you need to determine the value of x that makes 4x-1 equal to 15.<br>
4x-1 = 15
4x = 16
x = 4<br>
THAT is the value you need to substitute into the expression 4x^2+5 to get the answer.