35*14=490
35*(10+4)=490
490=490
35*40=1400
35*(4*10)=1400
1400=1400
= 3х + 18 - 3х = 18
= 25 - 5х - 25 = - 5х
= - 21 - 7х + 7х = - 21
= 18 - 9х - 18 = - 9х
= -12 + 6х -18 = 6х - 30
= - 24х - 20 + 24х = - 20
<span>а) -0,28* 4/7+5/7: 2 6/7=8/100+1/4=8/100+25/100=33/100</span>
б)(-2/3)^2*2 1/4 *(-3)=4/9*2 1/4*(-3)=1*(-3)=-3