when applying formula

Hi there,

I'm having trouble applying this formula:

𝐿𝑎=𝐿∞(1−𝑒^−𝐾(𝑎−𝑡zero))

where La= length at age of https://topfishingreel.com/, infinity =696, k=0.292, a= age +0.5 and Tzero =-0.365

I have:

=B15(1-EXP(-B16(B25-B17)))

but keep getting 

Any help is much appreciated:) Thank you