Answer:
Step-by-step explanation:
The rate if increase of side of square is 7cm/s
dL/dt=7
At what area is the area increasing
dA/dt=?
Areas of square is give to be 36cm²
Analysis
Let L be the length of each side of the square, a square has equal side.
Area of square is give as L²
Area=L²
L²=36
i.e L=√36
L=6cm
Therefore at t=0 L=6cm and A=36cm²
A=L²
dA/dL=2L
Given that, dL/dt=7
Multiply the two differential together
dA/dt= dA/dL × dL/dt
dA/dt= 2L × 7
dA/dt= 2×6×7
dA/dt= 84cm²/s
The rate of increase of the square is 84cm²/s
I don't like these computer choice thingies. It detracts from the math.


If we want to eliminate x we multiply the first equation by 5 then add it to the second:



OK, that's how it's done. Reading through the choices, that's choice D.
a
Step-by-step explanation:
because the circumference
Let's start with the question, how many questions do you need to get 88%?
so were are looking for
?/25 = 88% and 88% is also 0.88 so we can multiply 25 by 0.88
we get 22
But this doesn't here. the question asks us how many mistakes do you need. you can just subtract 22 from 25
25-22= 3
you need 3 misses to get 88%