=2,5 * 4 - 21 /3 *3/4 =10-21/4=19/4=4 3/4
|2.5| = 2.5
|-4| = 4
|2 1/3| = 2 1/3 = 7/3
|-3/4| = 3/4
2.5 * 4 - 7*3/(3*4) = 10 - 7/4 = 33/4 = 8 1/4
Ответ:
...=5/2/4=5/8
...=49/8/8=49/64