If we are eliminating x, we would multiply the 2nd equation by -5
5x + 18y = 23
x + 3y = 2....multiply by -5
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5x + 18y = 23
-5x - 15y = - 10 (result of multiplying by -5)
----------------add
0 + 3y = 13.....bye-bye x :)
Answer:
Step-by-step explanation:
The complex number -7i into trigonometric form is 7 (cos (90) + sin (90) i) and 3 + 3i in trigonometric form is 4.2426 (cos (45) + sin (45) i)
<h3>What is a complex number?</h3>
It is defined as the number which can be written as x+iy where x is the real number or real part of the complex number and y is the imaginary part of the complex number and i is the iota which is nothing but a square root of -1.
We have a complex number shown in the picture:
-7i(3 + 3i)
= -7i
In trigonometric form:
z = 7 (cos (90) + sin (90) i)
= 3 + 3i
z = 4.2426 (cos (45) + sin (45) i)




=21-21i
After converting into the exponential form:

From part (b) and part (c) both results are the same.
Thus, the complex number -7i into trigonometric form is 7 (cos (90) + sin (90) i) and 3 + 3i in trigonometric form is 4.2426 (cos (45) + sin (45) i)
Learn more about the complex number here:
brainly.com/question/10251853
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The answer is 62 B can u plz mark brainliest