Respuesta :

Answer:

Number of terms: n=6

Step-by-step explanation:

We are given:

a₁ = 0.75

r = 4

Sₙ = 1023.75

We need to find number of terms i.e n

The formula used will be:[tex]S_n=\frac{a(r^n-1)}{r-1}[/tex]

Putting values and fining n

[tex]S_n=\frac{a(r^n-1)}{r-1}\\1023.75=\frac{0.75(4^n-1)}{4-1}\\ 1023.75=\frac{0.75(4^n-1)}{3}\\3\times 1023.75=0.75(4^n-1)\\3071.25=0.75(4^n-1)\\4^n-1=\frac{3071.25}{0.75}\\4^n-1=4095\\4^n=4095+1\\4^n=4096[/tex]

We know that [tex]4^6= 4096[/tex]

[tex]4^n=4^6[/tex]

Using Exponent rule: [tex]a^n=a^b => n=b[/tex]

[tex]n=6[/tex]

So, Number of terms: n=6