Linear combination method just means to add the equations so that one variable with cancel. In this case the a values are already set up so that they will cancel.
2a + 3b = 1
-2a + b = 11
4b = 12
b = 3
now put 3 back into either of the original equations and solve for a.
2a + 3(3) = 1
2a + 9 = 1
2a = -8
a = -4
(-4,3)
Answer:
Step-by-step explanation:
hello :
sin x + 2 sin x cosx = 0 equivalent to : sinx(1+2cosx) =0
sinx=0 means : general solution is : x= kπ....k in Z
1+2cosx=0 means : cosx= -1/2 general solution is : x= ±π/6+kπ...k in Z
(A)
Step-by-step explanation:
All other choices will result in a negative number inside the radical sign.
For number 7 what is the formula for volume of a cube
The number of handshakes is the number of ways 6 objects can be selected 2 at a time.
.. C(6,2) = 6·5/(2·1) = 15
The appropriate choice is
... C) 15
_____
Consider that each person can shake hands with 5 others. That's a total of 6*5 = 30 handshakes, but it counts both A shaking with B and B shaking with A. If each pair of persons only shakes hands once, the number of handshakes is 30/2 = 15.