11) -x + y = -1 ; 2x - y = 0
y = -1 + x ; 2x - (-1+x) = 0 ⇒ 2x + 1 - x = 0 ⇒x = -1
y = -1 + (-1) ⇒ y = -2
12) -2x + y = -20 ; 2x + y = 48
y = -20 + 2x ; 2x + (-20 + 2x) = 48 ⇒ 2x -20 + 2x = 48 ⇒ 4x = 48 + 20
4x = 68 ⇒ x = 68/4 ⇒ x = 17
y = -20 + 2(17) ⇒ y = -20 + 34 ⇒ y = 14
13) 3x -y = -2 ; -2x + y = 3
y = 3 + 2x ; 3x - (3 + 2x) = -2 ⇒ 3x - 3 - 2x = -2 ⇒ x = -2 + 3 ⇒ x = 1
y = 3 + 2(1) ⇒ y = 3 + 2 ⇒ y = 5
14) x - y = 4 ; x - 2y = 10
x = 4 + y ; (4 + y) - 2y = 10 ⇒ 4 + y - 2y = 10 ⇒ 4 - y = 10
⇒ -y = 10 - 4 ⇒ -y = 6 ⇒ y = -6
x = 4 + (-6) ⇒ x = 4 - 6 ⇒ x = -2
15) x + 2y = 5 ; 3x + 2y = 17
x = 5 - 2y ; 3(5-2y) + 2y = 17 ⇒ 15 - 6y + 2y = 17 ⇒ -4y = 17 - 15
⇒ -4y = 2 ⇒ y = -2/4 ⇒ y = -1/2
x = 5 - 2(-1/2) ⇒ x = 5 + 2/2 ⇒ x = 5 + 1 ⇒ x = 6
If all three side lengths are INTEGERS and form PYTHAGOREAN TRIPLE then we know decimals are not allowed
if 24 and 51 are both legs then

x = 3177
and squre root of that gives us 56.364.... NOT an integer
So that means one of them is not a leg and since hypotenuse is longer than both legs, 51 must be the hypotenuse so to get the third side
![51^{2} - 24^{2} = x^{2}[tex] [tex] x^{2}](https://tex.z-dn.net/?f=%2051%5E%7B2%7D%20-%20%2024%5E%7B2%7D%20%20%3D%20%20x%5E%7B2%7D%5Btex%5D%20%5Btex%5D%20x%5E%7B2%7D%20)
=2025
x=45, leg B
Answer:
Lines 3 and 4
Step-by-step explanation:
Let's examine the slope of each of the given lines to have the exact value and be able to answer the question. We use the definition of: 
Line 1: 
Line 2: 
Line 3: 
Line 4: 
Line 5: 
Therefore the lines that have slope strictly greater than 1 and less than 2 are:
Lines 3 and 4