Respuesta :
- That part is total cookies as per algebraic formula x^2-(a+b)x+ab=0
Hence
The inequality is
[tex]\\ \rm\rightarrowtail x^2-30x+224>=0[/tex]
[tex]\\ \rm\rightarrowtail (x-14)(x-16)>=0[/tex]
[tex]\\ \rm\rightarrowtail x>=14,16[/tex]
Solution range
- [14,16]
Atleast means difference=16-14=2
Answer:
x² - 30x + 224 ≥ 0
Jessica has at least 2 cookies more than Martha
Step-by-step explanation:
Let x = number of cookies Jessica started with
Let y = number of cookies Martha started with
Given:
- They have 30 cookies in total between them.
⇒ x + y = 30
Given:
- Each of them ate 6 cookies from their bag. The product of the number of cookies left in each bag is not more than 80.
⇒ (x - 6)(y - 6) ≤ 80
Rewrite x + y = 30 to make y the subject:
⇒ y = 30 - x
Substitute this into (x - 6)(y - 6) ≤ 80 and rearrange:
⇒ (x - 6)(30 - x - 6) ≤ 80
⇒ (x - 6)(24 - x) ≤ 80
Expand and simplify:
⇒ 24x - x² - 144 + 6x ≤ 80
⇒ - x² + 30x - 144 ≤ 80
⇒ - x² + 30x - 224 ≤ 0
Divide both sides by -1 (remembering to change the direction of the sign):
⇒ x² - 30x + 224 ≥ 0
Comparing the inequality we have calculated with the inequality given, the missing number is 30.
Solve the inequality by factoring:
⇒ x² - 30x + 224 ≥ 0
⇒ x² - 16x - 14x + 224 ≥ 0
⇒ (x² - 16x) + (-14x + 224) ≥ 0
⇒ x(x - 16) - 14(x - 16) ≥ 0
⇒ (x - 16)(x - 14) ≥ 0
Checking inequalities:
If x > 16 then (x - 16)(x - 14) > 0
If x < 16 then (x - 16)(x - 14) < 0
If x > 14 then (x - 16)(x - 14) < 0
If x < 14 then (x - 16)(x - 14) > 0
Therefore,
x ≥ 16 or x ≤ 14
Given:
- x + y + 30
⇒ If x ≥ 16 then y ≤ 14
⇒ If x ≤ 14 then y ≥ 16
As Jessica (x) has MORE cookies than Martha (y), then only
If x ≥ 16 then y ≤ 14 is valid.
16 - 14 = 2
Therefore, Jessica has at least 2 cookies more than Martha