Question

14) Rezolvati urmatoarele ecuații, unde x este numar natural: a) 3(×+5)= 2 (×+10); b) 5(×-2)=3(x+4); c) 5(2×_5)=7(x+3)-19; d) 4 (3×+2)=2(4x+7)+2;

Answer 1

a) 3(×+5)= 2 (×+10)
3x+15=2x+20
3x-2x=20-15
x=5
b) 5(×-2)=3(x+4);
5x-10=3x+12
5x-3x=12+10
2x=22
x=22:2
x=11
c) 5(2×_5)=7(x+3)-19;
10x-25=7x+21-19
10x-7x=21-19+25
3x=27
x=27:3
x=9
d) 4 (3×+2)=2(4x+7)+2;
12x+8=8x+14+2
12x-8x=14+2-8
4x=8
x=8:4
x=2

Answer 2

3x+15=2x+20
3x-2x=20-15
x=5

5x-10=3x+12
5x-3x=10+12
2x=22
x=11