Answer:
see explanation
Step-by-step explanation:
Check the value of the discriminant
Δ = b² - 4ac
• If b² - 4ac > 0 then roots are real
• If b² - 4ac = 0 roots are real and equal
• If b² - 4ac < 0 then roots are not real
given (x - a)(x - b) = k² ( expand factors )
x² - bx - ax - k² = 0 ( in standard form )
x² + x(- a - b) - k² = 0
with a = 1, b = (- a - b), c = -k²
b² - 4ac = (- a - b)² + 4k²
For a, b, k ∈ R then (- a - b)² ≥ 0 and 4k² ≥ 0
Hence roots of the equation are always real for a, b, k ∈ R
Answer:
<u>Alejandro went to 8 matinee shows and 4 evening shows.</u>
<u>Our system of equations:</u>
<u>x + y = 12</u>
<u>7x + 12y = 104</u>
Correct statement and question:
Alejandro loves to go to the movies. He goes both at night and during the day. The cost of a matinee is 7 dollars. The cost of an evening show is 12 dollars.
Alejandro went to see a total of 12 movies and spent $ 104. How many of each type of movie did he attend? Write a system of equations.
Source:
Previous question that can be found at brainly
Step-by-step explanation:
Step 1:
Let x to represent the number of matinee shows Alejandro went to.
Let y to represent the number of evening shows Alejandro went to.
Now, let's write our system of equations:
x + y = 12
7x + 12y = 104
*********************
x = 12 - y
*********************
7 (12 - y) + 12y = 104
84 - 7y + 12y = 104
5y = 104 - 84
5y = 20
y = 20/5
<u>y = 4 ⇒ x = 12 - 4 = 8</u>
<u>Alejandro went to 8 matinee shows and 4 evening shows.</u>
The ratio of areas is the square of the scale factor, so that factor is
√(320/180) = 4/3
