Given the expressions:
[tex]\left(X-7\right)^2[/tex][tex]\mathrm{Apply\:Perfect\:Square\:Formula}:\quad \left(a-b\right)^2=a^2-2ab+b^2[/tex]Using FOIL:
[tex]\left(X-7\right)^2=X^2-2X\cdot\:7+7^2=X^2-14X+49[/tex]Similarly, given the expression provided, we obtain:
[tex]\left(3x-4\right)^2=\left(3x\right)^2-2\cdot\:3x\cdot\:4+4^2=\quad9x^2-24x+16[/tex]