Answer:
132 degrees
Step-by-step explanation:
these angles are Alternate interior angles so angle A is congruent to angle B.
5x-18 = 3x+42
-3x -3x
2x-18 = 42
+18 +18
2x = 60
÷2 ÷2
x=30
A=5(30) -18
= 150-18
= 132 degrees
HOPE THIS HELPS
Well if you're referring to rationalizing

, which simply means, getting rid of the pesky radical at the bottom
well, it boils down to, hmm say... a quantity or even a polynomial, multiplied times 1, is itself, 2*1=2, 3*1 = 3, ducks*1 = ducks, spaghetti * 1 = spaghetti
or whatever * 1 = whatever
and the value of the multiplicand, doesn't change in anyway, is the same thing before and after the multiplication by 1
now....1 can also be a fraction

so.. when you're doing

and the value multiplicand doesn't change in any way
now, try this in your calculator
Answer:
38 degrees
Step-by-step explanation:
this is an isosceles triangle, meaning that the base angles are congruent.
the total triangle is equal to 180
so the equation would be: x=180 - (71+71)
evaluate:
x=180-142
x=38 degrees
Hope this helps :)