107 - 17 - y = 15
90 - y = 15
y = 90 - 15
y = 75
107 - 17 - y = 15
90 - y = 15
y = 90 - 15
y = 75
tính tổng đại số sau
a)2-4+6-8+...+1998-2000
b)11-12+13-14+15-16+17-18+19-20
c)101-102-(-103)-104-(-105)-106-(-107)-108-(-109)-110
Tìm y biết:(2/11*13+2/13*15+2/15*17+2/17*19+2/19*21)*462-y=19
tim y biet [2/11*13+2/13*15+2/15*17+2/17*19+2/19*21]*462-y=19
Tìm y biết: (2/11*13 + 2/13*15 + 2/15*17 + 2/17*19 + 2/19*21) * 462 - y = 19
Tìm y biết :
( 2/11 * 13 + 2/13* 15 + 2/15 * 17 + 2/17 * 19 + 2/19* 21 ) * 462 - y = 19
(2/11*13+2/13*15+2/15*17+2/17*19+2/19*21)*462-y=19
2/(11*13)+2/(13*15)+2/(15*17)+2/(17*19)+2/(19*21)*462-y=19
1im cac so tu nhien x,y biet:
1. 252/x=84/97
2.x-2/255=114/153
3.50/19 nhan38/25<x<69/17+33/17
4.7/15<x/40<8/15
5.(1 1/4 -3/5):17/20<x/17<(5 1/3-3 1/2):12/17
6.y/15=2/5
7.3/x-7=27/135
help me
[2\11*13+2\13*15+2\15*17+2\17*19+2\19*21]*462-y=19
ai giải giúp mk đầu tiên mk tick cho