Răspuns :
Notam mama cu m, fiica cu f. Atunci,
m=f+20
m-4=3*(f-4)
=> (f+20)-4=3*(f-4)=3f-12
=> 16+12=3*f-f
=>2*f=28
f=14
=>m=20+14=34
m=f+20
m-4=3*(f-4)
=> (f+20)-4=3*(f-4)=3f-12
=> 16+12=3*f-f
=>2*f=28
f=14
=>m=20+14=34
m=f+20
m-4=3×(f-4)
m-4=3×f-12
f+20-4=3×f-12
f+16=3×f-12
2×f=28
f=14
m=20+14
m=34
m-4=3×(f-4)
m-4=3×f-12
f+20-4=3×f-12
f+16=3×f-12
2×f=28
f=14
m=20+14
m=34