Algebra 7- sinf Mavzu: Algebraik ifodalar mavzusida masalalar yechish

ALGEBRA

7-
sinf
Mavzu: Algebraik
ifodalar mavzusida masalalar yechish

O‘qituvchi: Yusupjonova Shahnoza Mirzatillayevna
-7,8·5;
7k-4,2m ;
0,5;
-7,8·5;
3a-1;
1/5+6m;
7k-4,2m ;
2020b²;
1000!;

1000!;
3a-1;
0,5;
1/5+6m;
2020b²;
Sonli ifodalar
Algebraik ifodalar
Algebraik ifodaning son qiymati…
Agar algebraik ifodaga kirgan harflar o‘rniga biror son qo‘yilsa va ko‘rsatilgan amallar bajarilsa, natijada, hosil qilingan son berilgan algebraik ifodaning son qiymatidir.
a = 2, b = 5 bo‘lganda, 3a + 2b – 7=?
3a + 2b – 7 = 3∙2+2 ∙5 – 7=16-7= 9
№16(2). p = , = 1da hisoblang:
+ = + =
= = =
= -2
№17(2). b= ; c=6; q=0,5; m=0,2
= =
= = = = 4
№19(1)Algebraik ifoda shaklida yozing:
Kichigi n ga teng bo‘lgan ikkita ketma-ket natural sonning yig‘indisi
Yechish: 1-son: n
2-son: n+1
n+n+1= 2n+1
Algebraik ifoda shaklida yozing:
2) Kattasi m ga teng bo‘lgan ikkita
ketma-ket natural sonning ko‘paytmasi;
Yechish: 1-son: m
2-son: m -1
(m-1)∙m= -m
№19(4) – topshiriq.
Kichigi 2p+1 ga teng bo‘lgan uchta ketma-ket toq natural sonning ko‘paytmasini algebraik ifoda shaklida yozing:
Yechish: 1-son: 2p +1
2-son: 2p +3
3-son: 2p +5
(2p+1)(2p+3)(2p+5)
№20
Shaklning perimetri va yuzini algebraik
ifoda ko‘rinishida yozing:
= ab:2
a
b
P= a+b+c
S = ab
c
P-?, S -?
- ?, - ?
= -
= -
1) = 2(2+a+1,5) = 7 + 2a
= 2(1,5 +2 -b) = 7 - 2b
= 7+2a-(7- 2b) = 7+2a-7+2b=
= 2a +2b

a
2
1,5
b
2) = 2(a+1,5) = 2a+3
= 1,5(2 -b) = 3 - 1,5b
= 2a + 3 - (3 - 1,5b) = 2a +1,5b
Javob: 2a + 2b va
2a + 1,5 b
№25 – masala(14-bet).
Geologlar o‘z yo‘nalishi bo‘yicha harakat qilib, otda soatiga c km tezlik bilan 3 soat-u 10 minut yurishdi; oqimning tezligi soatiga a km bo‘lgan daryoda oqim bo‘yicha 1 soat-u 40 minut solda suzishdi va soatiga
b km tezlik bilan 2 soat-u 30 minut piyoda yurishdi. Yo‘nalishning uzunligini s harfi bilan belgilab, geologlar bosib o‘tgan yo‘l formulasini yozing.
Agar a = 3,3 km/h, b = 5,7 km/h, c =10,5 km/h bo‘lsa,
Yonalishning uzunligini hisoblang.
Otda: = c km/h, = 3 soat-u 10 min. = 3 soat
Suvda: = a km/h, = 1 soat-u 40 min.= 1 soat
Piyoda: = b km/h, = 2 soat-u 30 min.= 2 soat
Agar a = 3,3 km/h, b = 5,7 km/h, c =10,5 km/h bo‘lsa,
Yechish: S = ++ S = V∙t
= 3 c;
S -? km
= 1 a;
= 2 b;
S = 3 c + 1 a +2 b
= 3 ∙10,5 + 1 ∙ 3,3 +2 ∙5,7=
= ∙ + ∙ + ∙ = 33,25 + 5,5 + 14,25 = 53(km)
TEST
Agar, = 3 bo‘lsa, algebraik ifodaning qiymatini toping.
A) 4 B) 8 C) 0 D) -8 E) -4
Yechish: = 3 dan, a = 3b (b≠o)
= = = 0
Javob: C) 0
MUSTAQIL BAJARISH UCHUN TOPSHIRIQLAR:
Darslikning 13- sahifasida
keltirilgan
14 -17- topshiriqlarni
bajarish.