Можете решить срочно, 9,10

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(10/21-25/28):(-11/14+24/35)=
=(40/84-75/84):(-55/70+48/70)=
=-35/84*(-70/7)=5/84*70=25/6=4 1/6

-2 2/3+2 1/3*(-15 3/7-(-4,8):4/15)=
=-2 2/3+2 1/3*(15 3/7-(-48/10):4/15)=
=-2 2/3+2 1/3*(15 3/7-(-48/10*15/4)=
=-2 2/3+2 1/3*(15 3/7+18)=
=-2 2/3+2 1/3*33 3/7=
= -2 2/3+7/3*231/7=-2 2/3+77=74 1/3