Answer:
Step-by-step explanation:
If two values are inversely proportional, their product must be maintained. That way, if one value goes up, the other goes down by the same extent.
Therefore, if 
and 
vary inversely, their product will be the same for all values of 
and 
.
Let 
and 
as given in the problem. Substitute values:
Hence, the maintained product is 
.
Thus, we have the following equation:
Substitute 
to find the value of 
when :
What is 0.00340.78 correct to 3 significant figures?
a significant fugure is when the number lean solething ,so its can anyone except 0
so if we are reducing 0.00340.78 to 3 significant number
first we have to look for the significant nulber ,which are 3,4,7,8
so the answer can be 0.0034.7
hopefully this helps
and 
use the second expression to calculate the left-hand side of the first equation:
Add 10 to both sides if this equation to get
and divide both sides by 2
this proves that x = 17, give the two initial equations
Hope this can help you :)
Start by getting one of the equations in terms of one variable, in this case lets put the first equation in terms of y
2x+y=3 ---> y=3-2x
now we plug that into the second equation
5x-2y=12 ---> 5x-2(3-2x)=12
we can then multiply and simplify
5x-2(3-2x)=12 ---> 5x-6+4x=12 ---> 9x-6=12 ---> 9x=18 ---> x=2
we can now plug x=2 into an equation to solve for y
2(2)+y=3 ---> 4+y=3 ---> y=-1
