630-x=500-210
630-x= 290
x= 630- 290
x= 340
<span>17:(3/5+1/4)+(7/8-1/4)*(4/5)^2=20 2/5
1. </span><span>3/5+1/4=12/20+5/20=17/20
2. 17:17/20=17*20/17=20
3. 7/8-1/4=7/8-2/8=5/8
4. (4/5)</span>²=16/25
5. 5/8*16/25=2/5
6. 20+2/5=20 2/5 или 20 4/10=20,4
Нет
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-1/4m+3/4n-3/4m-1/4 = -1m+2/4n=-1m+1/2n