Answer:
Part A:
x + y = 80
x + 20 = y
Part B:
Pam spends 30 minutes practicing math every day.
Part C:
It is not possible for Pam to have spent 60 minutes practicing dance because this means she must have practiced math for 40 minutes (60 - 20 = 40). This would total out to 100 minutes of total practice, not 80 minutes. Therefore, this is impossible.
Step-by-step explanation:
Part A:
"She spends 80 minutes every day practicing dance and math."
x + y = 80
"She dances for 20 minutes longer than she works on math."
x + 20 = y
Part B:
Solve for x:
x + 20 = y
Isolate variable x:
x = y - 20
Plug in this new value for the first equation:
y - 20 + y = 80
Combine like terms:
2y - 20 = 80
Isolate variable y:
2y = 100
y = 50
Plug in the new value of y into any equation:
x + 50 = 80
Isolate variable x:
x = 30
Part C:
x + 20 = y
x + 20 = 60
x = 40
x + y = 80
40 + 60 = 80
100 = 80
Impossible.
Answer:
8,000
Step-by-step explanation:
First there's 2,000 and if they double every 8 years. That means in the first 8 years it will double into 4,000. Lastly, the next 8 years it would double into the population being 8,000.
Answer:
Length = 20feet
Width = 10feet
Step-by-step explanation:
Area of a rectangle = LW
Perimeter P= 2(L+W)
L is the length
W is the width
If the length of a rectangle is twice as long as the width, then;
L = 2W
Substitute into the foemula
A = (2W)W
A= 2W²
If the area is 200ft², then;
200 = 2W²
100 = W²
W = √100
W = 10ft
Since L = 2W
L = 2(10)
L = 20ft
Hence the length of the rectangle is 20feet and the Width is 10feet
Answer:
X= 5, -9
Step-by-step explanation:
(X+2)² =49
Expand the bracket,
(X+2) (X+2)= 49
Apply the distributive property;
X(X+2) +2 (X+2) =49
X²+2X+2X+4=49
X²+4X+4=49
Move 49 to the left side of the equation;
X²+4X+4-49=0
X²+4X-45=0
Apply Factorisation method;
Consider the form
a²+bx+c=0
Find two numbers whose sum is equal to b and whose product is equal to c.
Comparing with our equation;
B =4 and C =45
We can use 9 and -5, this is because ;
9+(-5)=4 and 9*(-5)= 45.
Replace X +4X-45=0 with (X-5) (X+9)=0
Therefore;
X-5=0
X+9=0
Moving to the left side of the equation;
Therefore X= 5 and -9