1)
9x-14=139
9x=139+14
9x=153
x=153:9
x=17
2)
24x+112<136
24x<136-112
24x<24
x<24:24
x<1
3)
14x-3>193
14x>193+3
14x>196
x>196:14
x>14
4)
[4*(5+6x)]:(4*3)=(20+24x):12
5)
[5*(5+10x):(5*50)=(25+50x):250
6)
7+14+21+....+210=7*(1+2+3+....+30)=7*30*31:2=7*465=3255
3255:30=108,5
7)
Fie d un divizor comun cu care se simplifica atat numitorul cat si numaratorul
dI2n+5
dIn+2⇒dI2*(n+2)⇒dI2n+4
dI(2n+5)-(2n+4)⇒dI1
d=1
Fractia este ireductibila
8)
204:80(simplificam cu 2)
102:40(simplificam cu 2)
51:20⇒fractie ireductibila
100a+78+100a+78=200a+156
(200a+156):36(simplificam cu 4)
(50a+39):9⇒fractie ireductibila
PS: a=1,2,3,4,5,6,7,8,9
16^10=(4^2)^10=4^(2*10)=4^20
4^20:4^18=4^(20-18)=4^2=16=16:1⇒fractie ireductibila
