Question

Dau coronita!!!
a) (x-1)+2(x-2)+3(x-3)+4(x-4)=100
b) (x-1)+(x-2)+(x-3)+....+(x-11)=0
c) x+2x+3x+....+10x=550
d) (1-x)+(1-2x)+(1-3x)+....+(1-10x)=65​
Va rog ajutați-mă!

Answer 1

Răspuns:

a) (x-1)+2(x-2)+3(x-3)+4(x-4)=100

x-1+2x-4+3x-9+4x-16=100/+16

x-1+2x-4+3x-9+4x=116

x+2x+3x+4x=116+1+4+9

10x=130/:10

x=13