Answer:
For the first one I believe it is 90
Step-by-step explanation:
All I did to solve this was do 180 which is the diameter and divide by 2
Using a system of equations, it is found that David is 12 years old.
<h3>What is a system of equations?</h3>
A system of equations is when two or more variables are related, and equations are built to find the values of each variable.
The variables are given as follows:
- Variable z: Rebecca's age.
David is three times younger than the dad and twice as old as Rebecca, then:
Rebecca is 30 years younger than the dad, hence:
z = y - 30.
Then, since x = 2z and z = y - 30 and y = 3x, we solve for x to find David's age.
x = 2(y - 30)
x = 2(3x - 30)
x = 6x - 60
5x = 60
x = 60/5
x = 12.
David is 12 years old.
More can be learned about a system of equations at brainly.com/question/24342899
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Answer:
Solve for the first variable in one of the equations, then substitute the result into the other equation.
Point Form:
(
1
,
−
2
)
Equation Form:
x
=
1
,
y
=
−
2
Step-by-step explanation:
Graph.
y
=
3
x
−
1
y
=
x
+
1
y
=
−
x
−
1
y
=
x
+
1
Answer:
d) A = π(
)
Step-by-step explanation:
area = π 
diameter = 18
radius (half of diameter) = 9
area = π
