Question

Aflaţi valoarea necunoscutei:
{25+[14×15:2-5×(a×4-36:3)]}:5= 18
Va rog din tot sufletul ajuati ma !!!!

Answer 1

{25+[14×15:2-5×(a×4-36:3)]}:5= 18
25+[210:2-5x(ax4-12)] = 18x5 = 90
105-5x(ax4-12) = 90-25 = 65
5x(ax4-12) = 105-65 = 40
ax4-12 = 40:5 = 8
ax4 = 5+12 = 20
a = 20:4
a = 5

Answer 2

{25+[14×15:2-5×(a×4-36:3)]}:5=18
{25+[14×15:2-5×(a×4-36:3)]}:5=18
25+[210:2-5×(a×4-12)]=18×5 
25+[210:2-5×(a×4-12)] =90 
105-5×(a×4-12)=90-25
105-5×(a×4-12)=65
5×(a×4-12)=105-65
5×(a×4-12) =40
a×4-12=40:5
a×4-12=8
a×4 = 8+12
a×4=20
a=20:4
a=5