Answer:

Step-by-step explanation:
Multiply out
in order to find out which expression it is equivalent to.
1) Since the whole quantity is squared, write it out as
.

2) Multiply binomials by using the FOIL method. Multiply the terms that are listed first in each binomial, then the ones that are listed outermost when looking at both binomials, then innermost, and finally the last terms listed in each binomial. Simplify and combine like terms.


3)
, so
must be
. Thus,
is equivalent to -1. Knowing this, simplify and combine like terms.


Thus, it is equivalent to
.
<h3>
Answer: 10%</h3>
Work Shown:
2/20 = 0.10 = 10%
Note that 10% of 20 = 0.10*20 = 2 dollars is the sales tax to help confirm the answer.
Answer:
See the attached figure which represents the problem.
As shown, AA₁ and BB₁ are the altitudes in acute △ABC.
△AA₁C is a right triangle at A₁
So, Cos x = adjacent/hypotenuse = A₁C/AC ⇒(1)
△BB₁C is a right triangle at B₁
So, Cos x = adjacent/hypotenuse = B₁C/BC ⇒(2)
From (1) and (2)
∴ A₁C/AC = B₁C/BC
using scissors method
∴ A₁C · BC = B₁C · AC
0.15x + x <(or equal to) 50
Where x is the meal's cost (no tip included)
50 - 15% = 42.5.
x >(or equal to) 42.50.
(nothing is copied content, I copy pasted a number into the right position, feel free to check it mods)