Answer:
x = 1
Step-by-step explanation:
Given that y varies directly with x then the equation relating them is
y = kx ← k is the constant of variation
To find k use the condition y = 12 when x = - 2, then
k = 
= 
= - 6, thus
y = - 6x ← equation of variation
When y = - 6, then
- 6 = - 6x ( divide both sides by - 6 )
x = 1
The correct order is:
1. identify the variable
2. identify the operation
3. write an equation
4. solve the equation
5. check the solution
Good luck.
Answer: 10
Step-by-step explanation:
4 x 2 x 5 = 40
9 + 2 + 7 + 8 + 4 = 30
40 - 30 = 10
= 10
Answer:
The speed of the car is 75 mph.
The speed of the truck is 56 mph.
Step-by-step explanation:
Call the speed of the truck (x) miles per hour. As per the given information, the car is (19) miles per hour faster. Thus, one can form expressions to represent the speeds of the vehicles.
car = ( x + 19 ) mph
truck = ( x ) mph
Using the formula, ( (speed) * (time) = (distance) ), one can say that the speed of the car, times the time it took plus the speed of the truck times the time will equal the distance between the two vehicles:
(( car speed )( time )) + (( truck speed )( time )) = ( distance between vehicles )
Substitute,
( ( x + 19 ) ( 8 ) ) + ( ( x ) ( 8 ) ) = 1048
Simplify,
8x + 152 + 8x = 1048
16x + 152 = 1048
-152 -152
16x = 896
/16 /16
x = 56
Add (19) to find the speed of the car:
truck speed + 19
= 56 + 19
= 75
The speed of the car is 75 mph.
The speed of the truck is 56 mph.
Evaluate -y (y - 3) where y = -1:
-y (y - 3) = -(-(-1 - 3))
(-1)^2 = 1:
-1 - 3
-1 - 3 = -(1 + 3):
-(1 + 3)
1 + 3 = 4:
Answer: -4
