Answer:
x=2, z=4, y=-6
Step-by-step explanation:
Add
<u>-9x-y+2z= -4</u>
<u>-6x+y+5z= 2</u>
-9x-6x is -15x
-y+y is 0
2z+5z is 7z
-4+2 is -2
So the equation now looks like this: -15x+7z=-2
Subtract
<u>-6x+y+5z= 2</u>
<u>-4x+y+5z= 6</u>
So the equation will look like this:
<u>-6x+y+5z= 2</u>
<u>-(-4x+y+5z= 6)</u>
-6x+4x is -2x
y-y is 0
5z-5z is 0
2-6 is -4
So the equation now looks like this: <u>-2x=-4</u>
You can find x by dividing -2 on both sides:
<u>x=2 </u>
So 2 is x
Now you can substitute x into 2
-15(2)+7z=-2
-30+7z=-2
7z=28
Divide 7 on both sides:
<u>z=4</u>
So now you can substitute z into 4 (For any of the three equation)
-4(2)+y+5(4)=6
-8+y+20=6
20 minus 8 is 12
y+12=6
Subtract 12 on both sides:
y=-6
So the answers are
x=2, z=4, y=-6
Hope this helps!
Answer:
The volume of the regular tetrahedron is 283.5 m³
Step-by-step explanation:
The formula of the volume of the regular tetrahedron is V = 
A h, where
∵ The area of the base of a regular tetrahedron is 98.9 m²
∴ A = 98.9 m²
∵ The height of it is 8.6 m
∴ h = 8.6 m
→ Substitute them in the formula of the volume above
∵ V = (98.9)(8.6)
∴ V = 283.5133333 m³
→ Round it to the nearest tenth of a cubic meters
∴ V = 283.5 m³
∴ The volume of the regular tetrahedron is 283.5 m³
Answer:
you get 6.90372 so i thnk it is clse to B
Answer:
The are 8 dimes and 12 nickels
Step-by-step explanation:
1.We set n+d=20 because 20 is the total number of dimes and nickels in the jar.We have $0.05 n because for ever nickel,we earn $0.05.Adding this to the value of dimes,represented similarly by $0.1,then we set this to the amount of money we have in total,which is $1.40.
2.Subtract d from both sides of the first equation to get it by itself.Substitute-d for n in the second equation.The divide both sides by 0.5 to obtain the answer.
3.Substitute 8 in for d to obtain the value or n.
When we multiply two negative numbers, one always gets a positive number.
(-)×(-)= +
Hope it helps
