<span>92/23= 128/ ( 17+ a )
17+а=128*23\92
а=32-17
а=15</span>
А)15(3х-5)+6(7-2х)=
=45х-75+42-12х=
=45х-12х-75+42=
=33х-33
б)-8(-6+4у)+2(-18-11у)=
=48-32у-36-22у=
=48-36-32у-22у=
=12-54у
Х+320=80х7
х+320=560
х=560-320
х=240
240+320=80х7
560=560
<span>(-4/5)*(-3/8)*(5/12)=1/8
1)-4/5*5/12=-4/12=-1/3
2)-1/3*(-3/8)=1/8
===============
(-9/10)*5/6*(-2/3)</span>=1/2
1)5/6*(-2/3)=-5/9
2)(-9/10)*(-5/9)=5/10=1/2