Answer:
A: 68.25 minutes
B: 12 times
C: 42 mins and you decide this part I actually don't know. But I think it could be reasonable, after 40 times someone should get pretty good at it.
Step-by-step explanation:
a: 72 -0.75*5 = 68.25
b: M=63=72-0.75n
subtract 72 from each side: -9 = -0.75n
divide each side by -0.75: n = 12
so 12 times
c: 72 - 0.75(40) = 42 minutes. Now this could be is reasonable, but we don't know what their desert is. But 40 times is a lot of practice.
Number of questions worth 5 points = 10
Number of questions worth 2 points = 25
Further explanation:
The given system is a system of linear equations in two variables.
We will use the subsitution method to solve the system
Given equations are:

From equation no 1:

Putting x=35-y in second equation

Hence,
Number of questions worth 5 points = 10
Number of questions worth 2 points = 25
Keywords: Linear Equations, Substitution method
Learn more about substitution method at:
#LearnwithBrainly
<span>Let the width of the rectangular plot of land be 'x' yards.
Given that the length of the rectangular plot of land is 10 yards more than its width.
So, width of the rectangular plot of land = (x + 10) yards.
Also given that the area of the rectangular plot of land is 600 square yards.
We know that, area of a rectangle = length * width
That is, (x+10) * x = 600
x^2 + 10x = 600
x^2 + 10x - 600 = 0
x^2 + 30x - 20x -600 = 0
x(x + 30) - 20(x + 30) = 0
(x +30)(x -20) =0
Therefore, either (x + 30) = 0 or (x - 20) = 0
If x + 30 = 0, then x = -30 and
If x - 20 = 0, then x = 20
Since 'x' represents the width of a rectangular plot of land it cannot be negative.
Therefore,
width of the rectangular plot of land = 20 yards
length of the rectangular plot of land= x + 10 = 30 yards</span>