Answer:
n = -7,6
Step-by-step explanation:
n(n+1)+3=45
distributive property: a(b+c) = ab+ac
n²+n+3 = 45
n²+n -42 = 0
factor now
(n+7)(n-6) = 0
n = -7,6
11-5=6
18-11-7
26-18=8
........... so on and so forth.
I think you get the point.
Answer:

Kelly is correct.
Step-by-step explanation:
One person is able to plant 4 trees
Let x be the number of people
y be the number of trees
The situation is represented by

5 people are able to plant 20 trees

So, the situation is represented by 
Hence, Kelly is correct.
1) 55% is girls, then
100-55=45% is boys.
2) 45%=0.45 or 2) 400 ----100%
3)400*0.45= 180 boys x -----45% x=400*45/100=180 boys
Answer is 180 boys.
Answer:
The price of the tv before tax is 410
Step-by-step explanation:
Let x = price of tv before tax
tax = x* 9%
tax = .09x
The total cost is price of tv before tax plus tax
total cost = x + .09x
total cost = 1.09x
446.90 = 1.09x
Divide each side by 1.09
446.90/1.09 = 1.09x/1.09
410 = x
The price of the tv before tax is 410