Answer:
see explanation
Step-by-step explanation:
Given
x² - 2x - 4 = 0 ( add 4 to both sides )
x² - 2x = 4
To solve use the method of completing the square
add ( half the coefficient of the x- term )² to both sides
x² + 2(- 1)x + 1 = 4 + 1
(x - 1)² = 5 ( take the square root of both sides )
x - 1 = ± ( add 1 to both sides )
x = 1 ± , thus
x = 1 + or x = 1 -
Answer:
a. 4 : 1
b. 2 students
c. 3 : 1
Step-by-step explanation:
a. There were 12 students who got a C and 3 students who got As. The ratio is therefore:
12 : 3
Take it to the lowest form by dividing both sides by 3:
= 4 : 1
b. There were 4 students with a D grade and 8 with a B. The ratio is:
= 4 : 8
Taken to the lowest form that would be:
= 1 : 2
This means that for every student receiving a D, 2 students received an A.
c. 12 students received a C and 4 students received a D. That ratio is therefore:
= 12 : 4
Take to the lowest form by dividing both sides by 4:
= 3 : 1
