Answer:
The first one is correct
The second one is 20years
The third one is £8820
Step-by-step explanation:
Let the middle child be x
youngest child = x - 1
Oldest child = x + 1
(x - 1)^2 = 8(x + 1) + 4
x^2 - 2x + 1 = 8x + 8 + 4
x^2 - 10x - 11 = 0
(x - 11) * (x + 1) = 0
X = - 1 makes no sense. How can a middle child be - 1 years old?
x = 11
The youngest child is 10
The middle child is 11
The oldest child is 12
Check
=====
10^2 = 100
(8*12) + 4
96 + 4 = 100 So the results have been checked.
Minimum value is equal to x=8, y=-4
First find the derivative of the original equation which equals= d/dx(x^2-16x+60) = 2x - 16
at x=8, f'(x), the derivative of x equals zero, so therefore, at point x = 8, we have a minimum value.
Just plug in 8 to the original equation to find the answer for the minimum value.
Answer:
a) y= 8x+90 b) 154 pounds
Step-by-step explanation:
a) 90 will be the initial value (b) and 8 will be the slope (m)
this gives the linear function :
y = 8x + 90
b) to find his weight after 8 weeks plug in x=8
y= 64+90
y=154
154 pounds
