SOLUTION: Here is four questions that I need help with. 1. if log 90=x, then x= 3 2. if [x+2]=5, solve for x 3. given the following linear equations: 2x+3y=10 4x-6y=-

Question 148266: Here is four questions that I need help with.
1. if log 90=x, then x=
3
2. if [x+2]=5, solve for x
3. given the following linear equations:
2x+3y=10
4x-6y=-28
solve for (x,y) if there is a solution.
4. Multiply the complex numbers (3+2i)(3-2i)
thanks for your help
Answer by Alan3354(69443) (Show Source): You can put this solution on YOUR website!
1. if log 90=x, then x=
3
2. if [x+2]=5, solve for x
3. given the following linear equations:
2x+3y=10
4x-6y=-28
solve for (x,y) if there is a solution.
4. Multiply the complex numbers (3+2i)(3-2i)
-----------
1. I don't know what that 3 means. Ignoring it, the log(90)=1.95424...
If it means the log(90) to some base is 3, then the base is the cube root of 90, or apx 4.4814...
------------
2. x+2=5
x=3
--------
3. 2x+3y=10
4x-6y=-28
Using determinants
2 3 -10
4 -6 28
x = -1, y = 4
---------------
4. (3+2i)*(3-2i)
=
= 9 - (-4)
= 13

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