Answer: β ≠ ±1
Step-by-step explanation: For a system of equations to have an unique solution, its determinant must be different from 0: det |A| ≠ 0. So,
det ![\left[\begin{array}{ccc}1&\beta&1-\beta\\2&2&0\\2-2\beta&4&0\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%26%5Cbeta%261-%5Cbeta%5C%5C2%262%260%5C%5C2-2%5Cbeta%264%260%5Cend%7Barray%7D%5Cright%5D)
≠ 0
Determinant of a 3x3 matrix is calculated by:
det ![\left[\begin{array}{ccc}1&\beta&1-\beta\\2&2&0\\2-2\beta&4&0\end{array}\right]\left[\begin{array}{ccc}1&\beta\\2&2\\2-2\beta&4\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%26%5Cbeta%261-%5Cbeta%5C%5C2%262%260%5C%5C2-2%5Cbeta%264%260%5Cend%7Barray%7D%5Cright%5D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%26%5Cbeta%5C%5C2%262%5C%5C2-2%5Cbeta%264%5Cend%7Barray%7D%5Cright%5D)
![8(1-\beta)-[2(2-2\beta)(1-\beta)]](https://tex.z-dn.net/?f=8%281-%5Cbeta%29-%5B2%282-2%5Cbeta%29%281-%5Cbeta%29%5D)
β ≠ ±1
For the system to have only one solution, β ≠ 1 or β ≠ -1.
Answer:
19 > DB > 5
Step-by-step explanation:
In a triangle Δ ABC, AC = 7, and BC = 18.
Therefore, the length of the third side of the triangle Δ ABC i.e. length of AB can have a maximum value of < (7 + 18) i.e. 25 and the minimum value of the length AB will be > (18 - 7) i.e. 11
Hence, the length of AB will be given by 25 > AB > 11.
Now, AB = AD + DB = 6 + DB {Since length of AD is given to be 6}
Therefore, 25 > 6 + DB > 11
⇒ 19 > DB > 5 (Answer)
Answer:
x =3
Step-by-step explanation:
3(4x + 4) = 2(5x+9) - 12
First step is to open the brackets by multiplying. It becomes
3×4x + 3×4 = 2×5x + 2×9 -12
12x + 12 = 10x + 18 - 12
Collecting like terms on the right hand side and left hand side of the equation, it becomes
12x -10x = 18 -12 -12
2x = -6
Negative sign on the right hand side of the equation overwhelms the positive sign on left hand side of the equation. It becomes
2x = -6
x = -6/2 = -3
Checking
3(4×-3 + 4) = 2(5×-3+9) - 12
-24 = -12-12= -24
So x = -3
Answer:
1) 2019
2) 120-50=70
3) 2018
4) 100
5) 2018
6) 120-80=40
7) 2018
Step-by-step explanation:
1) 2019
2) 120-50=70
3) 2018
4) 100
5) 2018
6) 120-80=40
7) 2018
