2. Oldin qavslarni oching, soʻng hisoblang. Eslatma: qavs oldidagi + ishorasi yozilmaydi, ammo qavslarni ochishda hisobga olinadi

7-sinf algebra I-chorak

1. Koʻpaytirishni bajaring.

a)
1) 2) 3) 4)
b)
1) 2) 3) 4)
c)
1) 2) 3)


2. Oldin qavslarni oching, soʻng hisoblang. Eslatma: qavs oldidagi + ishorasi yozilmaydi, ammo qavslarni ochishda hisobga olinadi.
–54 + 275 – 12 = – (+54 – 275 + 12) =
= – (–209) = 209
1) – (83 + 31) + 61 2) + (–27 – 210) + 37
3) – (–27 + 48) + 38 4) 0,45 – (16– 0,35)


3. Qavslarni oching va soddalashtiring.
– (a + b + c)= – a – b – c
– (a – b – c)= –a + b + c
+ (–a – b + c)= – a – b + c
– (–a – (–b) + c)= a – b – c
1) (– a + b) – (a – b) 2) x – (x + y)
3) 5m – (m – 2) 4) p – (t – (p – t))
5) (– a + b) – (2a – b)
6) x – (– (5x + 4y) + 8y)
7) 5m – (2m – 5) 8) 3p – (t – (p – 2t))


4. Sonli ifodani arifmetik amallar xossalaridan foydalanib qulay usulda hisoblang.
7 ∙ 111 + 7 ∙ 8 =7 ∙ (111 + 8) = 777 + 56 = 833
1) 38 ∙ 25 + 38 ∙ 75
2) 2,9 ∙ 7,2 + 2,9 ∙ 2,8
3) 73 ∙ 89 – 73 ∙ 39
4) 17,5 ∙ 4,1 – 4,1 ∙ 7,5
5) 124 – 42 + 226 – 18
6) 2,51 – 4,41 + 3,49 – 6,59
7) 91 + 117 + 9 + 83
8) 31,11 + 42,89 – 1,8 – 5,2


5. Oʻxshash hadlarni ixchamlang
1) 3,5a –4,8b –3,5a –5,2b
2) 4a – 3a + 4,7 – 3,2
3) 2,4a – 3,7c + 2,7a – 2,2c
4) –9,3c + 5,4d + 2,1c + 2,2d + 4c
5) 4,2a + 1,8b – 2,6a + 3,4a
6) –3,9a + 1,7b – 4,1a – 5,5b