Answer:
C.
Step-by-step explanation:
Adding 2 fractions results in a fraction.
A+bi is a complex number
(3+2i)(a+bi)=17+7i
remember
i²=-1
so
expand and solve
a is the ral part
bi is the imaginary part
ok so
if Ac+Be=dc+fe where c=c and e=e then A=d and B=f
(3+2i)(a+bi)=17+7i
expand/distribute/FOIL
3a+2ai+3bi+2bi²=17+7i
3a+2bi+2ai+2bi=17+7i
3a-2b+2ai+2bi=17+7i
real parts are 3a-2b
imaginary is 2ai+2bi
so
3a-2b=17 and
2ai+2bi=7i
we need to solve
2nd equation, divide both sides by i
2a+2b=7
multiply by -1 and add to other equation
3a+2b=17
<u>-2a-2b=-7 +</u>
1a+0b=10
a=10
subsitue
2a+2b=7
2(10)+2b=7
20+2b=7
2b=-13
b=-13/2
the complex number is
10-(13/2)i or
10-6.5i
Answer:
Step-by-step explanation:
12.66-n=7.64
12.66-7.64=n
5.02=n
Let the 1st number be x; 2nd number be y; 3rd number be z.
x + y + z = 79
x = number we are looking for.
y = x * 5 ==> 5 times the first
z = x + 16 ==> 16 more than the first
Therefor,
x + (x * 5) + (x+16) = 79
1st step, multiply the 2nd number: x * 5 = 5x
x + 5x + x + 16 = 79
Add all like numbers:
7x + 16 = 79
To get x, transfer 16 to the other side and change its sign from positive to negative.
7x = 79 - 16
7x = 63
To get x, divide both sides by 7
7x/7 = 63/7
x = 9
To check. Substitute x by 9.
x + (x * 5) + (x+16) = 79
9 + (9 * 5) + (9 + 16) = 79
9 + 45 + 25 = 79
79 = 79 equal. value of x is correct.
