Answer:
-1 1/2
Step-by-step explanation:
Answer:
x = 1, y = -1
Step-by-step explanation:
If we have the two equations:
and 
, we can look at which variable will be easiest to eliminate.
looks like it might be easy to get rid of, we just have to multiply by 2 and y is gone (as -6y + 6y = 0).
So let's multiply the equation by 2.
Now we can add these equations
------------------------
Dividing both sides by 5, we get 
.
Now we can substitute x into an equation to find y.
Hope this helped!
Answer:
C
Step-by-step explanation:
6:4=8:12
6x3=8
4x3=12
Answers + Step-by-step explanation :
a) the equation should be:
7(n + 5) = 91 since you first add 5 to n and then multiply it by 7. The answer is 91 so that is on the other side of the equal sign
b) we can solve our equation to find for n, the number jim thought of
7(n + 5) = 91
I will use the distributive property.
7n + 35 = 91
Subtract 35 on both sides
7n = 56
Now divide 7 on both sides to find n
n = 8
The number Jim was thinking of was 8! this should be correct, hope this helps!
Answer:
a) W₁ = 78400 [J]
b)Wt = 82320 [J]
Step-by-step explanation:
a) W = ∫ f*dl general expression for work
If we have a chain with density of 10 Kg/m, distributed weight would be
9.8 m/s² * 10 kg = mg
Total length of th chain is 40 m, and the function of y at any time is
f(y) = (40 - y ) mg where ( 40 - y ) is te length of chain to be winded
At the beggining we have to wind 40 meters y = 0 at the end of the proccess y = 40 and there is nothing to wind then:
f(y) = mg* (40 - y )
W₁ = ∫f(y) * dy ⇒ W₁ = ∫₀⁴⁰ mg* (40 - y ) dy ⇒ W₁ = mg [ ∫₀⁴⁰ 40dy - ∫₀⁴⁰ ydy
W₁ = mg [ 40*y |₀⁴⁰ - 1/2 * y² |₀⁴⁰ ⇒ W₁ = mg* [ 40*40 - 1/2 (40)² ]
W₁ = mg * [1/2] W₁ = 10*9,8* ( 800 )
W₁ = 78400 [J]
b) Now we can calculate work to do if we have a 25 block and the chain is weightless
W₂ = ∫ mg* dy ⇒ W₂ = ∫₀⁴⁰ mg*dy ⇒ W₂ = mg y |₀⁴⁰
W₂ = mg* 40 = 10*9.8* 40
W₂ = 3920 [J]
Total work
Wt = W₁ + W₂ ⇒ Wt = 78400 + 3920
Wt = 82320 [J]
