Simplify the given expression: (6 + 2i) − (8 − 3i)
the minus sign out front in - (8 -3i) means -1*(8 - 3i) distribute the -1 ... which means multiply each term inside the parens by -1 then combine "like terms" (add up the reals, and add up the imaginaries)
-8+3i
yes, now you have 6 + 2i -8 +3i combine "like terms"
in other words, (6-8) + (2i + 3i)
-2+5i
yes
ok that was given
wt about this
Simplify the given expression: (−5 + 3i) • (1 − 2i)
do you know FOIL? or in general , how to multiply for example (x+y)(a+b) ?
-5+6i
sry that was the wrong question to ask
-5-6i
? what is the question?
This is it Simplify the given expression: 4 divided by the quantity of 3 minus 2i
\[ \frac{4}{3-2i} \] multiply top and bottom by 3+2i can you do that?
12-8i
what did you get for (3-2i)(3+2i) ? (the bottom part)
the top part is 4(3+2i) = 12+8i we need the bottom part (3-2i)(3+2i)
12+8i top, 13 bottom
so the answer is \[ \frac{12}{13} + \frac{8}{13} i \] not very pretty or simple, but at least it is in standard a+ bi form
Next question
Simplify the given expression: (4 + 2i) − (1 − 7i)
same idea as the one at the top. can you do it?
oh, nvm i got it
thx
another one
(−5 + 3i) • (1 − 2i)
i messed up on it i think
do you know FOIL?
i got 5i-6
-5-6i
how?
you can use the distributive Law or FOIL (same thing, but a way to remember it)
Are you asking how I got it wrong or how I got to this answer?
how did you get that answer? what steps did you do?
i did the foil method, so i got -6isquared + 5 -5
but it has to be simplified
here is using the distributive law: A (x+y) = Ax + A y (−5 + 3i) • (1 − 2i) in this case, A is (-5 + 3i), and we write (-5 + 3i)* 1 + (-5 + 3i)(-2i) now use the distributive property a second time (twice) the first part 1*(-5 + 3i) is easy : -5 + 3i the 2nd part: -2i*(-5) + (3i)*(-2i) = +10i -6i^2 so we get -5 + 3i +10i -6i^2 which should match the terms you get if you use FOIL next, remember i^2 or i*i is -1 <--- IMPORTANT SIMPLIFICATION in other words, we have -5 + 3i +10i -6*-1
now simplify and combine like terms
oh ok, thx
what is an extraneous soulution
oh ok, so here's the question
4Square root of x minus 3 = 12, solve for x and identify if it is an extraneous solution
is it not extranuous
x = 0
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