So since angle A is 120, so angles B+C=60 because there are 180 degrees in a triangle. So B:C is 2:1. So angle B is 40 and angle C is 20.
Answer:
<h2>x = -2 or x = 4</h2>
Step-by-step explanation:
The zeros:
(x + 2)(x - 4) = 0 ⇔ x + 2 = 0 or x - 4 = 0
x + 2 = 0 <em>subtract 2 from both sides</em>
x = -2
x - 4 = 0 <em>add 4 to both sides</em>
x = 4
<u>Corrected Question</u>
In the year 2009, the cost of a flat screen television can be modeled by the equation C = -10t^2 + 500 where t is the number of years since 2009. Factor this cost polynomial.
Answer:

Using express exponents, you write C=10(50-t^2)
Step-by-step explanation:
To factor the cost polynomial,
, we follow these steps.
Step 1: Determine the greatest common divisor of the terms in the polynomial
The terms in the polynomial are 
The greatest common divisor of
is 10.
Step 2: Factor the polynomial by dividing each of the terms with the greatest common divisor obtained above.

Answer:
Let x be the number.
Given the statement: Three sets of a sum of a number and four are added to the sum of seven times the same number and thirteen.
" sum of a number and four" translated to x + 4
"Three sets of a sum of a number and four" translated to 3(x+4)
"sum of seven times the same number and thirteen" translated to 7x + 13
then;
the expression for the given statement become;

Using distributive property: 

Combine like terms;

Therefore, the simplified expression for Three sets of a sum of a number and four are added to the sum of seven times the same number and thirteen. is, 