6000 x a + 2000 x b = 98000
a + b = 25
a = ?
b = ?
6000 x a + 2000 x b = 98000
a + b = 25
a = ?
b = ?
Tìm x:
a) x + 285 = 2094
b) x - 45 = 5605
c) 6000 - x = 2000
a) x + 285 = 2094
x = 2094 - 285
x = 1809
b) x - 45 = 5605
x = 5605 + 45
x = 5650
c) 6000 - x = 2000
x = 6000 - 2000
x = 4000
Tính nhẩm :
a) 3000 + 13000 – 6000 = ……………
b) 3000 x 4 = ……………
c) 25000 : 5 = ……………
d) 2000 x 3 : 2 = ……………
Hướng dẫn giải:
a) 3000 + 13000 – 6000 = 10000
b) 3000 x 4 = 12000
c) 25000 : 5 = 5000
d) 2000 x 3 : 2 = 3000.
Tính nhẩm
a) 50000 + 40000 = .......................
90000 - 20000 = .......................
b) 42000 + 6000 = .......................
86000 - 2000 = .......................
c) 40000 x 2 = .......................
80000 : 4 = .......................
d) 12000 x 3 = 3.......................
72000 : 8 = .......................
a) 50000 + 40000 = 90 000
90000 - 20000 = 70000
b) 42000 + 6000 = 48000
86000 - 2000 = 84000
c) 40000 x 2 = 80000
80000 : 4 = 20000
d) 12000 x 3 = 36000
72000 : 8 = 9000
90000
70000
48000
84000
80000
16000
9000
Tính nhẩm:
a) 3000 + 5000 = ..........
5000 + 5000 = ..........
4000 + 4000 = ..........
7000 + 2000 = ..........
6000 + 1000 = ..........
2000 + 8000 = ..........
b) 2000 + 700 = ..........
100 + 1000 = ..........
6000 + 600 = ..........
8000 + 500 = ..........
5000 + 300 = ..........
400 + 6000 = ..........
a) 3000 + 5000 = 8000
5000 + 5000 = 10 000
4000 + 4000 = 8000
7000 + 2000 = 9000
6000 + 1000 = 7000
2000 + 8000 = 10 000
b) 2000 + 700 = 2700
100 + 1000 = 1100
6000 + 600 = 6600
8000 + 500 = 8500
5000 + 300 = 5300
400 + 6000 = 6400
a) 3000+5000=8000
5000+5000=10000
4000+4000=8000
7000+2000=9000
6000+1000=7000
2000+8000=10000
b) 2000+700=2700
100+1000=1100
6000+600=6600
8000+500=8500
5000+300=5300
400+6000=6400
a) 3000 + 5000 = 8000
5000 + 5000 = 10000
4000 + 4000 =8000
7000 + 2000 = 9000
6000 + 1000 = 7000
2000 + 8000 = 10000
b) 2000 + 700 = 9000
100 + 1000 = 1100
6000 + 600 =12000
8000 + 500 = 13000
5000 + 300 = 5300
400 + 6000 = 6400
Tính nhẩm:
a) 3500 + 200 = ..............
3700 - 200 = ..............
7100 + 800 =..............
7900 - 8000 = ..............
4400 + 300 = ..............
4700 - 3000 = ..............
b) 6000 + 2000 = ..............
8000 - 6000 = ..............
8000 - 2000 = ..............
7000 + 3000 = ..............
10 000 - 7000 = ..............
10 000 - 3000 = ..............
2000 + 8000 = ..............
10 000 - 2000 = ..............
10 000 - 8000 = ..............
a) 3500 + 200 = 3700
3700 - 200 = 3500
7100 + 800 = 7900
7900 - 8000 = 7100
4400 + 300 = 4700
4700 - 3000 = 4400
b) 6000 + 2000 = 8000
8000 - 6000 = 2000
8000 - 2000 = 6000
7000 + 3000 = 10 000
10 000 - 7000 = 3000
10 000 - 3000 = 7000
2000 + 8000 = 10 000
10 000 - 2000 = 8000
10 000 - 8000 = 2000
tìm x biết:
a,(3x+ 1) x ( x-2000)x (3x +6000) = 0
b, (3x-1)^2 = 169
c,|2x+5|=1/2
d, x-6 / x-7= x+1 / x-3
e, (x-5)x30 / 100=20x/100 + 5
a) pt a <=> 3x+1=0 hoặc x-2000=0 hoặc 3x+6000=0
<=> x=-1/3 hoặc x=2000 hoặc x=-2000
Tính nhẩm:
5000 + 100 = ..................
7400 - 400 = ..................
2000 3 + 600 = ..................
8000 : 2 + 2000 = ..................
6000 - (5000 - 1000) = ..................
6000 - 5000 + 1000 = ..................
7000 - 3000 x 2 = ..................
(7000 - 3000) x 2 = ..................
5000 + 100 = 5100
7400 - 400 = 7000
2000 3 + 600 = 6600
8000 : 2 + 2000 = 6000
6000 - (5000 - 1000) = 2000
6000 - 5000 + 1000 = 2000
7000 - 3000 x 2 = 1000
(7000 - 3000) x 2 = 8000
5000 + 100 = 5100
7400 - 400 = 7000
2000 3 + 600 = 6600
8000 : 2 + 2000 = 6000
6000 - (5000 - 1000) = 2000
6000 - 5000 + 1000 = 2000
7000 - 3000 x 2 = 1000
(7000 - 3000) x 2 = 8000
5000 + 100 = 5100
7400 - 400 = 7000
2000 3 + 600 = 6600
8000 : 2 + 2000 = 6000
6000 - (5000 - 1000) = 2000
6000 - 5000 + 1000 = 2000
7000 - 3000 x 2 = 1000
(7000 - 3000) x 2 = 8000
Cho ba số a b c thỏa mãn 25a+b+2c=0. Đặt f(x) a*x2+b*x+c. Chứng minh f(-3). f(4)<,= 0