• 1)12000:6=2000
2)2000×7=14000
3)24000:8=3000
4)28000+14000=42000
5)42000-3000=39000
• 1)700×5=3500
2)3×500=1500
3)3500-1500=2000
• 1)6000×3=18000
2)18000:2=9000
3)9000×6=54000
4)81000:9=9000
5)54000-9000=45000
• 1)800×3=2400
2)2400:6=400
3)21:7=3
4)400-3=397
• 1)48:8=6
2)45000:9=5000
3)6+5000=5006
4)5006-1=5005
• 1)600×7=4200
2)200×6=1200
3)4200-1200=3000
(x+y)²-(x-y)²/x³y³=((x+y-x+y)(x+y+x-y))/x³y³=2y*2x/x³y³=4xy/x³y³=4/x²y²
при x=2 y=√5 4/(2²(√5)²)=4/(4*5)=1/5
4) 4,48/8,96=0,5
5) 10,8/13,5=0,8
6) 8,32/5,2=1,6
3^(2x-5)+3^(2x-6)-3^(2x-7)-3^(2x-8) = 3^(2x-8)(27 + 9 - 3 -1) = 3^(2x-8)* 32
3^(2x-8)* 32 ≤ 32
3^(2x-8) ≤ 1
2x - 8 ≤ 0
x ≤ 4