Question

Aflati pe x din :
x+9<13
2·x+3$\leq$12
2·x+3<12
2+x:4+21:3$\leq$31

Answer 1

x+9<13 ⇔x<13-9⇔x<4
2·x+312⇔2·x≤12-3⇔2·x≤9⇔x≤9/2⇔x≤4·1/2
al treilea identic dar semnul este <
2+x:4+21:331⇔2+x:4+7≤31⇔x:4≤31-2-7⇔x:4≤22⇔x≤22·4⇔x≤88