Answer:
Step-by-step explanation:
-7x + 12 + (-8x + 48) = 180
-15x + 60 = 180
-15x = 120
x = -8
m<BDC= -7(-8)+ 12 = 56 + 12 = 68
m<CBA = -8(-8)+48 = 64+48 = 112
Answer:
Solving the given linear system, we get x = 1 and y = -3.
The solution set is: (1,-3)
Step-by-step explanation:
We need to solve the linear system of equations.

We can write second equation y=x-4 as: 
Let:

Now, Adding equation 1 and 2

So, we get x = 1
Now, put value of x in second equation to find value of y:

So, we get y = -3
Solving the given linear system, we get x = 1 and y = -3.
The solution set is: (1,-3)
Answer:
7 hours 30min
Step-by-step explanation:
Step one :
Given data
We are told that Erica can paint 1 room in 5hours
Her work rate is 1/5 room per hour
And also with the assistance of her friend they can paint 1 room in 3 hours
Hence their combined work rate is 1/3 room per hour
Step two
The combined work expression is
1/A+1/B=1/T
Where A=Erica's work rate
B=Rachael's work rate
T=combined work
1/5+1/B=1/3
1/B=1/3-1/5
1/B=5-3/15
1/B=2/15
B=15/2
B=7.5 hours
It will take Rachel 7 hours 30min to paint the room
Answer:
It’s going by 2
Step-by-step explanation:
If you go up it goes to negative and if you go down it goes to positive