Respuesta :

mhanifa

Answer:

  • a₁ = 4

Step-by-step explanation:

Given

  • d = - 1
  • a₇ = - 2

Find a₁

Use the nth term equation of AP

  • aₙ = a₁ + (n - 1)d

Apply to the given case and solve for a₁

  • - 2 = a₁ + 6(- 1)
  • - 2 = a₁ - 6
  • a₁ = 6 - 2
  • a₁ = 4
semsee45

Answer:

[tex]a_1=4[/tex]

Step-by-step explanation:

Arithmetic sequence

General form of an arithmetic sequence: [tex]a_n=a+(n-1)d[/tex]

where:

  • [tex]a_n[/tex] is the nth term
  • a is the first term
  • d is the common difference between terms

Given:

  • [tex]a_7[/tex] = -2
  • d = -1

Therefore:

[tex]\implies a_7=-2[/tex]

[tex]\implies a+(7-1)(-1)=-2[/tex]

[tex]\implies a-6=-2[/tex]

[tex]\implies a=4[/tex]

Therefore:

[tex]\implies a_1=4[/tex]