Answer: 9 elm trees were removed.
Step-by-step explanation:
Let x represent the number of elm trees removed.
The total number of elm trees in the park is 22. Elm leaf beetles have been attacking the trees. After removing several of the diseased trees, there are 13 healthy elm trees left. The equation to find the number of elm trees that were removed would be
x + 13 = 22
Subtracting 13 from the left hand side and the right hand side of the equation, it becomes
x + 13 - 13 = 22 - 13
x = 9
Answer: x=3 and y=−2
Step-by-step explanation:
x=−2y−1;4x−4y=20
Step: Solve x=−2y−1 for x:
Step: Substitute−2y−1 for x in 4x−4y=20:
4x−4y=20
4(−2y−1)−4y=20
−12y−4=20(Simplify both sides of the equation)
−12y−4+4=20+4(Add 4 to both sides)
−12y=24
−12y
−12
=
24
−12
(Divide both sides by -12)
y=−2
Step: Substitute−2 for y x=−2y−1:
x=−2y−1
x=(−2)(−2)−1
x=3(Simplify both sides of the equation)
Answer:
Question 16
(a) x < 1 : the values of x are smaller than than 1 (e.g. possible values are 0, -1, -2, etc) and since the circle is not shaded it means that 1 isn't a possible value of x
(b) x 
-2 : the circle is filled therefore -2 is included in the answer
Question 17
(a) unfilled dot above -2 and arrow pointing to the left
(b) shaded circle above 4 with and arrow pointing to the right →
Answer: 18.75 for each girl
Step-by-step explanation:
First you take the unit rate 2.50 multiply by 5.
2.50 x 5 = 12.50
12.50 x 3 = 37.50
37.50 / 2 = 18.75
