namely, let's rationalize the denominator in the fraction, for which case we'll be using the <u>conjugate</u> of that denominator, so we'll multiply top and bottom by its <u>conjugate</u>.
so the denominator is 5 + i, simply enough, its conjugate is just 5 - i, recall that same/same = 1, thus (5-i)/(5-i) = 1, and any expression multiplied by 1 is just itself, so we're not really changing the fraction per se.

Step-by-step explanation:
29,30,31 is three consecutive interger that add up to 90
We let x be the length (in minutes) of a certain science class. 65% of this period is spent with the experiment which lasted for about 52 minutes. Mathematically, this can be expressed as,
52 = (0.65)(x)
The value of x from the generated equation is 80. Thus, the science class is 80 minutes long.
3x=x+40
Subtract x from both sides
2x=40
Divide both sides by 2nto get x by itself
x=2
Plug 2 in for x
m∠4 = (3x)
m∠4 = 3(2)
Solve
m∠4 = 6