20 POINTS!!! URGENT!! EXERCICE 4 STP

1.)

[tex] \frac{1}{4} + \frac{2}{3}* \frac{3}{4} [/tex]=
[tex] \frac{1}{4} + \frac{6}{12} [/tex]=
[tex] \frac{3}{12} + \frac{6}{12} [/tex]=
[tex] \frac{9}{12} = \frac{3}{4} [/tex]