Verified answer

[tex]\frac{43^{3}-17^{3}}{26} +43*17=\frac{(43-17)(43^{2}+43*17+17^{2})}{26} +43*17=\frac{26(43^{2}+43*17+17^{2})}{26} +43*17=\\\\=43^{2}+43*17+17^{2}+43*17=43^{2}+2*43*17+17^{2}=(43+17)^{2}=60^{2}=3600[/tex]