Tính, 1/20+2/35+3/70+4/140+5/266+6/475
1 tìm x
140% x X + 0,5 x X = 0,57
2. So sánh M và N
M= ab5+43c N = a34+4bc
3. Tính A
1/17+7/170+3/70+2/35+1/20
1.tìm x
a)320+(218-x)=475
b)315-6/x=275
c)4*(x-15)+32=64
d)7*x+120/5=63
e)(120-4*x)*(x-17)=0
g)8*x-20=140
m)132-5*(20-x)=92
n)15*(44-2*x)=30
v)38/(2*x+18)=2
1 tìm x
140% x X + 0,5 x X = 0,57
2. So sánh M và N
M= ab5+43c N = a34+4bc
3. Tính A
1/17+7/170+3/70+2/35+1/20
Tính nhanh : 20 x 35 x 70 x 140 x 280 x 560 x 1120 x 2240 x 4480 =?
1.tính bằng cách thuận tiện nhất.
a)1/10+2/20+3/30+4/40+5/50+6/60+7/70+8/80+9/90
=
=
Tính nhanh:
a,1/4+2/5+6/8+9/15+8/1
b,1/2+2/4+3/6+4/8+5/10+6/12+7/14+8/16+9/18+10/20
c,1/10+4/20+9/30+16/40+25/50+36/60+49/70+64/80+81/90
Tính nhanh:
a,1/4+2/5+6/8+9/15+8/1
b,1/2+2/4+3/6+4/8+5/10+6/12+7/14+8/16+9/18+10/20
c,1/10+4/20+9/30+16/40+25/50+36/60+49/70+64/80+81/90
tính nhanh
a, 4/5 * 3/7 + 4/5 * 4/7
b, 20 * 45 + 55 * 20/35 * 1996 - 1991 * 35
c, (1 - 1/2) * (1 - 1/3) * (1 - 1/4) * (1 - 1/5)