Answer:
See explanations below
Step-by-step explanation:
Given the system of equation
2x - 10 y = -30 ... 1
x - 5y = 20 ... 2
Step: From 2;
x = 20 + 5y ...3
Step 2: Substitute equation 3 into 1
2x - 10y = -30
2(5y+20) - 10y = -30
Open the bracket
10y + 40 - 10y = -30
10y - 10y + 40 = -30
0+40 = -30
40 = -30
The steps taken by Teri are correct all through. He didn't make any error whatsoever
Answer:
the answer is 9
Step-by-step explanation:
Answer
Formula

where r is the radius of a circle.
As shown in the image
Diameter of the circle = 16 .3 cm

= 8.15 cm
Put in the formula

As


= 51.2 cm (approx)
Therefore the circumference of a circle is 51.2cm (approx) .
Option (D) is correct .
Answer:
Step-by-step explanation:
The straight line equation is:
y = m*x + b Where m is the slope of the line and b the intercept with y-axis, in our case y is the depth of the tank and x (time in lapsus of 3 hours).
The slope m = ( y₂ - y₁ ) / (x₂ - x₁)
We have point A ( 3 , 8 ) and point B ( 6 , 7 )
m = ( 6 - 3 ) / (7 - 8 ) m = -3
We see that each 3 hours time-depth decreases 1 in.
Then to find the depth at the beginning of x-axis
At noon 12 tank was 9 inches, three hours before at 9 in the morning the depth was 10 inches and:
9 in the morning 10
6 in the morning 11
3 in the midnight 12
12 in the night 13
Then 13 is the intercept with y-axis
then the equation is:
h = - 3*x + 13
Note x is time in lapsus of 3 hours
Answer:
The total number of unbroken / working slots
Step-by-step explanation:
Given that Devin's DVD case has 3 rows of slots, but 5 slots are broken
Also given that the number of slots in a row is x
1 row has x slots
3 rows has y slots
on cross multiplication we get y = 3x
ie there are a total of 3x slots in the 3 rows
Given that out of these 3x slots 5 . of the slots are broken
Therefore the total number of working slots = total number of slots - number of slots which are broken
total number of working slots are = 3x - 5
Therefore the given expression is the number of working / good slots