Answer:
80
Procedure in attached file
Hope it helps
So we have the following system of equations:

We need to solve it by substitution. This means that we have to take the expression for x given by the second equation and replace x with it in the first equation:

So y=-1. If we use this value in the second equation:

So we have x=2 and y=-1 which means that there's one solution. Then the correct answer is A and the solution is (2,-1).
This is the answer that i was going to upload :
the answer is +5(or)-5 because of root
Answer:
There are 42 different types of shirt available for this company.
Step-by-step explanation:
Given:
Number of design Company has = 3
Number of color pattern available = 7
Types of shirt (short or long sleeves) = 2
We need to find the number of different types of shirts are available from this company.
Solution:
the number of different types of shirts can be calculated by multiplying Number of design Company has with Number of color pattern available also multiplying with Types of shirt (short or long sleeves).
framing in equation form we get;
the number of different types of shirts 
Hence There are 42 different types of shirt available for this company.
Answer:
<h2>
£1,330.46</h2>
Step-by-step explanation:
Using the compound interest formula 
A = amount compounded after n years
P = principal (amount invested)
r = rate (in %)
t = time (in years)
n = time used to compound the money
Given P = £1200., r = 3.5%, t = 3years, n = 1 year(compounded annually)

Value of Charlie's investment after 3 years is £1,330.46