Answer:
First choice.
Step-by-step explanation:
You could plug in the choices to see which would make all the 3 equations true.
Let's start with (x=2,y=-6,z=1):
2x+y-z=-3
2(2)+-6-1=-3
4-6-1=-3
-2-1=-3
-3=-3 is true so the first choice satisfies the first equation.
5x-2y+2z=24
5(2)-2(-6)+2(1)=24
10+12+2=24
24=24 is true so the first choice satisfies the second equation.
3x-z=5
3(2)-1=5
6-1=5
5=5 is true so the first choice satisfies the third equation.
We don't have to go any further since we found the solution.
---------Another way.
Multiply the first equation by 2 and add equation 1 and equation 2 together.
2(2x+y-z=-3)
4x+2y-2z=-6 is the first equation multiplied by 2.
5x-2y+2z=24
----------------------Add the equations together:
9x+0+0=18
9x=18
Divide both sides by 9:
x=18/9
x=2
Using the third equation along with x=2 we can find z.
3x-z=5 with x=2:
3(2)-z=5
6-z=5
Add z on both sides:
6=5+z
Subtract 5 on both sides:
1=z
Now using the first equation along with 2x+y-z=-3 with x=2 and z=1:
2(2)+y-1=-3
4+y-1=-3
3+y=-3
Subtract 3 on both sides:
y=-6
So the solution is (x=2,y=-6,z=1).
Distribute 1/2 to <span>(n – 4):
</span>
<span>
Subtract (2n + 3):
</span>
<span>
Your equation should now look like this:
</span>
<span>
Combine like terms on both sides:
</span>
<span>
Subtract 1/2n from both sides:
</span>
<span>
Divide both sides by -5/2 to get n by itself:
</span>
<span>
The value of n is
2.</span>
Answer:
1/16
Step-by-step explanation:
Both 5 and 80 can be divided by 5.
This reduces the ratio of 5/80 to 1/16.
11 lbs 5 oz - 1 lb 15 oz...we are gonna have to borrow...there is 16 oz in a lb.
11 lbs 5 oz....we r going to borrow 1 lb from the right side and add it to the left side making it 10 lbs and 21 oz...u see what I did...I borrowed 1 lb from the right side and added 16 oz to the left.Now we can subtract.
10 lbs 21 oz - 1 lb 15 oz = 9 lbs 6 oz <== ur answer
speed of current is 1.5 mi/hr
Answer:
let the rate in still water be x and rate of the current be y.
speed down the river is:
speed=distance/time
speed=14/2=7 mi/h
speed up the river is:
speed=(14)/(3.5)=4 mi/hr
thus total speed downstream and upstream will be:
x+y=7...i
x-y=4.......ii
adding the above equations i and ii we get:
2x=11
x=5.5 mi/hr
thus
y=5-5.5=1.5 mi/r
thus the speed in still waters is 5.5 mi/hr
speed of current is 1.5 mi/hr
