Zdroj TeX:

\small \vec e_1'=([k+s_1(1-k)]-[s_1(1-k)],[s_2(1-k)]-[𝑠_2(1-k)])=\pmb{(k,0)};\\ \small \vec e_2'=([s_1(1-k)]-[s_1(1-k)],[k+s_2(1-k)]-[𝑠_2(1-k)])=\pmb{(0,k)}