Answer:
Step-by-step explanation:
a) 2,3,4,5,6,7
b)4,6,7
Step-by-step explanation:
answer is first option,,,
Answer:
System of equations:
20x + 30y = 650
x + y = 25
Time underwater = 10 hours
Time at the surface = 15 hours
Step-by-step explanation:
Let x = time underwater at 20 km/h.
Let y = time on the surface at 30 km/h.
speed = distance/time
distance = speed * time
distance underwater: 20x
distance on the surface: 30y
total distance: 650
20x + 30y = 650
total time: x + y
total time: 25
x + y = 25
20x + 30y = 650
x + y = 25
20x + 30y = 650
-20x - 20y = -500
--------------------------------
10y = 150
y = 15
x + y = 25
x + 15 = 25
x = 10
Answer:
y = 3 - 2x
Step-by-step explanation:
The goal is to isolate the y variable
In order to have y by itself (on one side of the equation or equal sign), we must move the other numbers and variables to the other side.
Since 2x is on the same side as y, we have to subtract it from both sides. Subtracting it cancels out the original 2x and leaves the equation to look like this:
y = 3 - 2x
Now the y is isolated
Another example:
-5x + y = 15
To isolate the y, we must cancel out the -5x. Add 5x to both sides. It will cancel out the -5x and bring it to the right side of the equation, resulting in:
y = 15 + 5x
First do 12-5, which equals 7. Next, subtract 1/10 from 2/5. 2/5 is the same as 4/10 if you multiply both the numerator and denominator by 2. 4/10-1/10=3/10. Now add 7 and 3/10. You will get 7 3/10 as the answer, which is letter C.)
