Answer:
3 groups of 5
Explanation:
if x is the number of groups of four, and y is the number of groups of five, then 4x +5y =39 (four students per group of four times the # of groups of four, and 5 students per group times the # of groups of five, which should equal the total amount of students, 39). also, x+y=9. (number of each type of group = 9 groups total).
then, use these two equations and solve for y, by "canceling out" x. there are many ways to do this, but i'm going to use subtraction.
4x-5y=39
x+y=9
you want to change the equation
x+y=9
into
4x+4y=36
by multiplying the whole equation by four. because in order to cancel out the x, you need it to equal zero. in the first equation, its 4x.
so its now
4x-5y =39 MINUS
4x+4y=36
___________
y=3
you can check your work because the remaining 6 groups of four (24 total students) plus the 3 groups of five (15 total students) adds up to equal 36
The correct answer is - B) the water quality of the stream.
By studying the fish populations and their well being, the watersheds, as well as the composition of the water, the scientists are trying to keep track of the situation of the quality of the water in the stream.
The fish populations, their activity, well being, are always a nice indicator about the water quality, as they live in it and are directly effected by any negative changes in the water quality.
The watersheds can also show a partial picture of the quality of the water in the streams, and that is because the water passes through them before entering the stream itself, so a clean and healthy watershed, often means good quality of the water.
The most relevant indicator of the quality of the water in the stream is still the testing of the water itself, where the water composition can be examined in detail thus to be determined its condition.
Answer:
No
Explanation:
There muscles are not strong enough to handle this kind of weighh
Answer:
Tools used in Lower Paleolithic era were mainly cleavers, choppers, and hand axes. These tools were mainly used for cutting, digging, and skinning the prey. These tools were found from Belan Valley of Mirzapur (U.P.), Didwana in Rajasthan, Narmada Valley, and from Bhimbetka (near Bhopal, M.P.).
Answer:
2H2O
Explanation:
Given that,
H2SO4 2NaOH → Na2SO4
We know that,
The number of atoms of the reactant and the number of atoms of the product is equal in the reaction.
Therefore,
H2SO4 2NaOH → Na2SO4+2H2O
Hence, the additional product balances the reaction is 2H2O
