Area of a square = length²
A = x²
16 = x²; x = 4
dA/dx = 2x cm²/s
dx/dt = 6 cm/s
Using chain rule:
dA/dt = dA/dx * dx/dt
dA/dt = 2x * 6
dA/dt = 12x
At x = 4,
dA/dt = 12(4) = 48 cm²/s
Answer:
53 marks
Step-by-step explanation:
To sue a linear equation to solve the given problem, we must assign a function to the score of one of them. Let the score of Azmah be N. Then given that Azmah scored 17 marks more than Yazid, Yazid's score will be
= N - 17
Given that Suzana's score is twice of Yazid's score, then Suzana's score
= 2(N - 17)
If their total score is 161 then
N + N - 17 + 2(N - 17) = 161
4N = 161 + 51
4N = 212
N = 53 . This is Azmah's score
Answer:
x = 6
Step-by-step explanation:
Given that x and y vary directly then the equation relating them is
y = kx ← k is the constant of variation
To find k use the condition x = 25 when y = 100 , then
100 = 25k ( divide both sides by 25 )
4 = k
y = 4x ← equation of variation
When y = 24 , then
24 = 4x ( divide both sides by 4 )
6 = x
11km = 5h
1km = 5h divide by 11km = 0.45h
16.5km = 0.45 x 16.5 = 7.42 h