Answer:
I am going to show you the first steps to complete squares for the given equation: 1) Starting equation: 3x^2 + 9x -4 = 0 2) Add 4 to both sides => 3x^2 + 9x - 4 + 4 = 4 => 3x^2 + 9x = 4 3) Extract common factor 3 in the left side => 3 (x^2 + 3x). Now, compare with a(x^2 + 3x) and you get a = 3. Answer: a = 3.
This problem can be expressed through the equation:
x+3x+10= 90
To solve it we subtract 10 on both sides
→x+3x=80
Add x and 3x
→4x=80
And divide each side by 4
→x=80/4
→x=20
ANSWER:
20
<span>a1 = 3
an = a (n-1) +7</span>