75%=0,75
28*0,75=21(уч.)
* - умножение
1) 4,28*(7,4+2,6)=4,28* 10=42,8
2) 38,4*(71,6-71,5)=38,4*0,1=3,84
3) 9,18*(123,5-122,5)=9,18*1=9,18
4) 5,6*(0,68+0,19-0,85)=5,6*0,02=0,112
<span>9 *15* 2=9*(15*2)=9*30=270
</span>50*4*3=(50*4)*3=200*3=600
<span>(77+19)+51=77+(19+51)=77+70=147
</span><span>(623+1200)+800=623+(1200+800)=623+2000=2623
</span><span>18+(32+7)=(18+32)+7=50+7=57
</span><span>327+(33+589)=(327+33)+589=350+589=839</span>
19х-15х=96
4х=96
х=96:4
х=24