Hey there!
Use this formula:

Remember this formula.
Now, let's solve the given problem.

Hope this helps you!
~Just a joyful teen

Hope this helps and have a fantabulous day! :)
7a)
x - 10 + x - 11 + 3x + 6 = 180
5x -15 = 180
5x = 195
x = 39
7b)
y = 3x + 6
y = 3(39) +6
y = 117 + 6
y = 123
Answer: $11836.8
Step-by-step explanation:
Given. That :
Amount invested = $5000
Interest rate = 9% = 0.09
Period = 10 years, compounded annually
Using the compound interest formula :
A = p(1 + r/n)^nt
A = final amount
P = principal or invested amount
r = rate of interest
n = number of times interest Is applied per period
t = period
A = 5000(1 + 0.09/1)^(1*10)
A = 5000(1.09)^10
A = 5000 * 2.36736367459211723401
A = 11836.81837296058617005
= $11836.8
(x+4)^2 + (y-3)^2 = 4
Which means, radius is 2, center is (-4,3)
8x + By + 92 = 0
(-4; 12) ⇒ x = -4; y = 12
subtitute
8 · (-4) + 12B + 92 = 0
-32 + 12B + 92 = 0
12B + 60 = 0 |subtract 60 from both sides
12B = -60 |divide both sides by 12
B = -5