7. 30 ta oquvchidan \( 3 x+1 \) tasi rus tilini, \( 2 x-1 \) tasi ingliz tilini, \( x-1 \) tasi rus tilini ham ingliz tilini ham biladi. I tasi esa rus tilini ham ingliz tilini ham bilmaydi, Nechta oquvehi rus tilini biladi? \( \begin{array}{llll}\text { A) } 19 & \text { B) } 13 & \text { C) } 17 & \text { D) } 11\end{array} \)

\( z(x+y) ; \) use \( x=6, y=8 \), and \( z=6 \)

A bus driver has a tax credit of \( € 60 \) a week and pays income tax on all his wages standard rate of \( 20 \% \). If he pays \( € 140 \) in income tax for the week, find his gross weekly wage.

2) \( a-5-b ; \) use \( a=10 \), and \( b=4 \)

posible: \( -10+2)=(-6+2) \cdot(-7+3) \)

Determinar si es falso o verdadero: Sean \( H_{1} \) y \( H_{2} \) subespacios de un espacio vectorial \( V \). Entonces \( H_{1} \cap H_{2} \) es un subespacio de \( V \).