Respuesta :
Last one absolutely(We need quadratic equation not inequality here)
Let's check again for confirmation
[tex]\\ \rm\rightarrowtail x^2-40x+300=0[/tex]
[tex]\\ \rm\rightarrowtail x^2-30x-10x+300=0[/tex]
[tex]\\ \rm\rightarrowtail (x-30)(x-10)=0[/tex]
[tex]\\ \rm\rightarrowtail x=30,10[/tex]
X has values 30 and 10
Rob has highest means atleast 30
Answer:
B. x² - 40x + 300 ≥ 0
C. 30
Step-by-step explanation:
Let x = number of balloons Rob started with
Let y = number of balloons Loretta started with
Given:
- There were 40 balloons between both bags
⇒ x + y = 40
Given:
- Rob used 8 balloons from his bag, and Loretta used 8 balloons from hers. The product of the number of balloons left in each bag is no more than 44.
⇒ (x - 8)(y - 8) ≤ 44
Rewrite x + y = 40 to make y the subject:
⇒ y = 40 - x
Substitute into (x - 8)(y - 8) ≤ 44 and simplify:
⇒ (x - 8)(40 - x - 8) ≤ 44
⇒ (x - 8)(32 - x) ≤ 44
⇒ 32x - x² -256 + 8x ≤ 44
⇒ - x² + 40x - 256 ≤ 44
⇒ - x² + 40x - 300 ≤ 0
Dividing both sides by -1 (remembering to change the direction of the inequality sign):
⇒ x² - 40x + 300 ≥ 0
Factor x² - 40x + 300 ≥ 0
⇒ x² - 10x - 30x + 300 ≥ 0
⇒ (x² - 10x) + (-30x + 300) ≥ 0
⇒ x(x - 10) -30(x - 10) ≥ 0
⇒ (x - 10)(x -30) ≥ 0
Therefore, x ≤ 10 or x ≥ 30
As x + y = 40:
If x ≤ 10 then y ≥ 30
If x ≥ 30 then y ≤ 10
If Rob (x) had MORE balloons than Loretta (y) then only
If x ≥ 30 then y ≤ 10 is valid
Therefore, the least number of balloons Rob could have had before using any is 30.