Răspuns :
(2x-30):15+15=315
(2x-30):15=315-15
(2x-30):15=300
2x-30=300×15
2x-30=4500
2x=4500+30
2x=4530
x=4530:2
x=2265
PROBA :
înlocuim pe x =>
(2×2265-30):15+15=
=(4530-30):15+15=
=4500:15+15=
=300+15=
=315 (adevarat )
(2x-30):15=315-15
(2x-30):15=300
2x-30=300×15
2x-30=4500
2x=4500+30
2x=4530
x=4530:2
x=2265
PROBA :
înlocuim pe x =>
(2×2265-30):15+15=
=(4530-30):15+15=
=4500:15+15=
=300+15=
=315 (adevarat )