To simplify 4/(2+7i), we multiply it by a fraction equal to one that removes the i value in the denominator. The best value to do this is the complex conjugate divided by itself, so we have 4(2-7i)/((2+7i)(2-7i)). Simplifying, we have (8-28i)/(4-(-49))=(8-28i)/53, which is a completely simplified fraction since 8 and 53 are relatively prime (or coprime), and there are no radicals in the denominator.
Answer:
I don't understand the question
Step-by-step explanation:
price difference= $45-$36
=$9
now,
x% of $45=$9
or, x/100 ×45 =9
or, x/20 ×9=9
or, x/20=1
therefore, x= 20%
Answer:
The unknown dimension is 35
Step-by-step explanation:
The perimeter of a rectangle is l+l+w+w or 2l+2w (l=length, w=width)



then we subtract 14 from 84



Let's check our answer

<u>Hope this helps :-)</u>
Answer:
42
Step-by-step explanation:
168 factors into
2•2•2•3•7
two of the 2's make a perfect square
(2•2)•2•3•7
2²•2•3•7
as none of the product of the remaining factors makes a perfect square
2•3 = 6, 2•7 = 14, 3•7 = 21
we need to multiply the remaining factors together to find another perfect square
2²•(2•3•7)²
2•3•7 = 42
42(168) = 7056 = 84²