1. (, , ) !
2. Ec , , !
( ( ) . , .)
3. , , . ( .)
4. !
5. , , . , (!) , : , , .
6. , , . , (!) .
7. , .. .
1. , ( 3, 4, 11, 13, 23, 27-37; 3).
2. , .
3. ( , 5, 88)
4. ( 30, 3).
1. ( ), : 2 x (: 2 x x), 2 z +3 y ( z y).
2. , :
) , : a (b +3) ( a b 3), 3(x + y) ( 3 x y);
) , : (b +3)× a ( b 3 a), (x + y)×3 ( x y 3).
, .
.
|
|
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1. .
.
x . 1
. 1
1) xy = 18-6 = 12 (.);
2) x:y = 18:6 = 3;
......................................................
6) 2 x +3 y = 2×18+3×6 = 36+18 (.);
7) (2 x): (3y) = 36:18=2;
.
2. .
1.
|
850
? , 2
? , 300
850+850×2+ 850300=1700+1700300=3100 ()
: 3100 .
2.
|
850
?, 850×2=1700
?, 850300=550
850+1700+ 550=1400+1700=3100 ()
: 3100 .
3. .
1.
| 52 | 52 | ||
| 52 | 52 | ||
| 52 | +52 |
: 52.
2.
x ; y ; x-y .
(x52) y=(xy)52, .. 52.
x (y52)=(xy)+52, 52
: 52.
3.
52 52, 52.
4. .
) :
1.
| (/) | () | () | |
| ( ) | ? | ||
 2
| |||
| ? |
72:42=182=16 (/)
1) 72:4=18 (/) .
2) 182=16 (/)
: 16 /.
2 ( ).
 ? /
| ? /, 4 , 72 | |
| 2 / |
1.
| (/) | () | () | |
| ( ) | ? | ||
| 2
| |||
| ? |
126:7+126:63=18+2=20 (/)
1) 126:7=18 (/) .
2) 126:63=2 (/) ().
3) 18+2=20 (/) .
: 20 /.
2 ( ).
? /
| ? /, 7 , 126 | ||||
| () | 
| ? /, 63 , 126 |
) :
(150: (60+15)) 15=30 ()
1) 60+15=75 (/) .
2) 150:75=2 () .
3) 15×2=30 () .
: 30 .
) :
(200+250) 40 = 1800 ()
1) 200+250=450 (/)× .
2) 450×40=1800 ()
: 1800 .
) :
.
65 / 90 /
3 ,?
(9065) ×3=75 ()
1) 9065=25 (/) .
2) 25×3=75 ()
: 75 .
5. .
.
|
|
|
 |
M N
| : AB=50 AM=15 NB=19 | . MN=ABAMNB=501915=26 () : 26 . |
| : MN |
.
| : MNPQ MN= k NP=7 k PQ= k8 k= 13 | . lMNPQ= MN+ NP+PQ= k+7k+k8 =9 k 8 (); 9×138=1178=109 () : 9 k 8; 109 . |
| : lMNPQ |
.
| : AB= b CD=c DE= d AF=a | . 1) CC1=DE=A1F=d, C1E=CD=c, AB=C1F=b; BC=AA1=AF A1F=ad; EF=C1FC1E=bc; I : PABCDEF=AB+BC+CD+DE+EF+FA=b+ (ad) +c+d+ (bc)+ a= =2a+2b II : PABCDEF=PABC1F =AB+BC1+C1F+FA=a+b + a+b=2a+2b 2) SABCDEF=S ABC1F S CDEC1=AB × AFCD × DE=a × b c × d; SABCDEF=S ABCA1 + S A1DEF=AB × AA1 DE × EF=b ×(ad)+ d ×(bc) : PABCDEF=2a+2b; SABCDEF= b ×(ad)+ d ×(bc), SABCDEF = a × b c × d. |
| : PABCDEF SABCDEF |
