Question

Urgent!! Dau coroana!!! ​

Answer 1

Explicație pas cu pas:

1) a1=-3

a2= a1+r=(-3)+(-2)=-5

a3=-5+(-2)=-7

S3=(-3)+(-5)+(-7)=-3-5-7=-15

2) b1=-3

b2=b(2-1)×q=b1×(-2)=(-3)×(-2)=6

b3=6×(-2)=-12

S3=b1(q la puterea n -1)/(q-1)=[(-3)×(-2)³-1]/(-2)-1=-3×[(-8)-1]/-3=-3×(-9)/-3=27/-3=-9

3) x=?

a1=2x-5

a2=3x

a3=-10

a2=(2x-5)+r=3x

2x-3x=5-r

-x=5-r|×(-1)

x=-5+r=r-5

a3=(r-5)+r=2r-5=-10

2r=-10+5

r= -5/2

a2=a3-r= -10-(-5/2)=-10+5/2=(-20+5)/2=-15/2

=>(2x-5)+(-5/2)=-15/2

2x=-15/2+5/2

2x=-10/2=-5

x=-5/2