Which of the following violates the principle of dimensional homogeneity $($select all which apply$)?(F=$ force, $x=$ distance, $u=$ velocity, $P=$ pressure,$=$ density, $a=$ acceleration $).$

$F{}^{-1}=x^2{u}^2$

$FP={}^2{a}^2{x}^4$

$x=P{u}^{-1}$

$Pa=u^3$