Question

1. 7x-4 mai mic decât 31.

2. Media aritmetica a patru numere este 75.afla numerele.

3. 11+12+........+100=5(1000x-1)

4. (123x-1278):149=36

Answer 1

1.7x<31+4
7x<36
x<5,14
x=0,1,2,3,4,5

2. a+b+c+ supra 4 =75
a+b+c+d=300

3.100x101:2-(1+2+3+....+10)=5(1000x-1)
50x101-10x11:2
5050-5x11
5050-55
4995=5(1000x-1)
1000x-1=4995:5
1000x-1=999
1000x=1000
x=1

4.123x-1278=5364
123x=6642
x=54