Question

Găsiţi numărul natural x care verifică egalitatea:
a) x+25+75=400
b)1+2+3+...+10+x=3000

Answer 1

a)  x+25+75=400

x=400-75-25
x=300

b) 1+2+3+...+10+x=3000

10*11:2+x=3000
55+x=3000
x=3000-55=2945

Answer 2

x+25+75=400
x+100=400
X=400-100
x=300

1+2+3...10+x=3000
10(10+1):2+x=3000
10•11:2+x=3000
110:2+x=3000
55+x=3000
x=3000-55
x=2945