Question

b) Află valoarea numărului necunoscut din egalitatea:
[(5× a +178)×15 + 90]: 45 = 63.

Answer 1

[(5a+178)x15+90]:45=63
(75a+2670+90):45=63
75a+2760=63x45
75a+2760=2835
75a=2835-2760
75a=75
a=1

Answer 2

[(5× a +178)×15 + 90]: 45 = 63
(5xa+178)x15+90=63x45
(5xa+178)x15+90=2835
(5xa+178)x15=2 835-90
5xa+178=2745:15
5xa+178=183
5xa=183-178
5xa=5
a=5:5
a=1