The answer is C. go with it.
5x + y = 9....multiply by 7
10x - 7y = -18
----------------
35x + 7y = 63 (result of multiplying by 7)
10x - 7y = -18
----------------add
45x = 45
x = 45/45
x = 1
5x + y = 9
5(1) + y = 9
5 + y = 9
y = 9 - 5
y = 4
solution is : (1,4)
=========================
-4x + 9y = 9
x - 3y = -6 ....multiply by 4
----------------
-4x + 9y = 9
4x - 12y = -24 (result of multiplying by 4)
---------------add
- 3y = - 15
y = -15/-3
y = 5
x - 3y = -6
x - 3(5) = -6
x - 15 = -6
x = -6 + 15
x = 9
solution is : (9,5)
Remark
The number of faces reaching out in the 3rd dimension of the pyramid = the number of edges on the base.
Givens
Number of edges (or sides on the base)= e
Number of faces = f
Formula
F = e + 1 Don't forget that the base is also a face.
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a ) Two matrices cannot be multiplied.
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b )
The answer is | 20 - 4 - 12 |
| 8 2 19 - |
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Answer:
Step-by-step explanation:
2x + 3y = 2
x = 2 - 3y /2
x + y = 0
substitute the value of x
+ y = 0
2 - 3y + 2y = 0
2 = y
again,substitute the value of y
x = 2 - 3y / 2
=2 - 3*2 / 2
=2 - 6 / 2
=-2