(5x-10)2=100
+ 5x-10=10
5x=20
x=4
+ 5x-10=-10
5x=0
x=0
tick cho cái
( 5X - 10 )2 = 100
( 5X - 10 )2=102hoặc ( 5X - 10 )2=(-10)2
5X - 10=10 5X - 10=-10
5X=10+10 5X =-10-10
5X=20 5X=-20
x=20:5 5X=-20:5
x=4 X=-4
Vậy X=4 hoặc X=-4
( 5X - 10 )2 = 100
( 5X - 10 )2=102hoặc ( 5X - 10 )2=(-10)2
5X - 10=10 5X - 10=-10
5X=10+10 5X =-10-10
5X=20 5X=-20
x=20:5 5X=-20:5
x=4 X=-4
Vậy X=4 hoặc X=-4
(5x-10)2=100
+ 5x-10=10
5x=20
x=4
+ 5x-10=-10
5x=0
x=0
(5x-10)2=100
+ 5x-10=10
5x=20
x=4
+ 5x-10=-10
5x=0
x=0
bai 1; cho tong M =126 +213+x. Tim x de M chia het cho 3
bai 2; chung to rang tong ; A= 2 + 2 mu 3 + 2 mu 4 + 2 mu 5 + 2 mu 6 +2 mu 7 +2 mu 9 + 2 mu 10 + 2 mu 12 chia het cho 5
bai 1 ;chung minh rang abcd chia het 99 thi ab cong cd chia het 99 va nguoc lai
bai 2;a.8 mu 10 tru 8 mu 9 tru 8 mu 8 chia het 55
b.7mu 6 cong 7 mu 5 tru 7 mu 4 chia het 11
d.10 mu 9 cong10 mu 8 cong 10 mu 7 chia het 555
c.81mu 7 cong 27 mu 9 tru 9 mu 13 chia het 45
bai 1;tim x biet ; a, 2 . (x-3)=5mu2-7 b, 23-2 mu 2 . ( x+4)=3 mu 3 -6 c, x . 2 mu 4 -3 mu 2 =7 mu 2 -(5 mu 2 -13)
bai 2 ; tinh hop li ;
a, 43.75 +43.25 b, 14.73+2.7 .37 -28.5 c, 34.56+44.17 .2+100.66
bai 5 ;tinh a,{92-[(4 mu 2 +71.2mu2);15]}-13
b, 360;{300;[150-5 mu 2 . (10 -2 mu3 )]}
bai 1; so sanh
a, 3 mu 600 va 2 mu 900 b, 2 mu 360 va 3 mu 240
c, 3 mu 236 va 2 mu 354
bai 2,tim x biet ;
a,5 mu x + 5 mu x +2 =650
b, 2 mu x +3 +5 nhan 2 mu x +2 - 2 mu x + 1 = 208
bai 3,tinh tong;A=3 + 3 mu 2 + 3 mu 3 +3 mu 4 +.........+3 mu 2019 +3 mu 2020
bai 4 , tinh gia tri bieu thuc ;
a,A=2 mu 1 + 2 mu 2 +2 mu 3 +......+2 mu 2019
b, B=1+3+3 mu 2 +3 mu 3 +......+3 mu 2020
a, 5x - 10 . ( - 7 ) = 15 .( - 3 )
b, 2x + 12 = - 8
c, 3x - 5 = - 20
d, 2x - ( - 12 ) = ( - 8 ) . 23
e, x mu 2 = 49
i, ( x - 2 ) mu 2 + 1 = 65
g , 2. ( x - 3 ) mu 2 - 5 = 5 . ( - 3 ) mu 2
bai 1 ; chung to rang ;
a, 10 mu 5 + 35 chia het cho 5 va 9
b, 10 mu 5 + 98 chia het cho 2 va 9
giup minh gap di ai nhanh minh nhan like mai minh can roi
tim cac so nguyen x,y,z bt {5x-7} mu 2 cong {6 tru 5y } mu2 cong {5z } mu 2 bang 10
Cach lam bai (× - 4):5=2mu 4 - 3 mu 2
(2×-9):5=7
4(×-3)= 5 mũ 2 - 1 mũ 10
Nhanh nha sap hoc them oi
