Some "easy" questions need a prompt with (1 Viewer)

[davidbarnes]

So we've done all these before, its just some I've forgotton how to do some, etc and woudl just like to see how to do one so that I can then practice with some similar ones. I'm not looking for answers, I'm looking for solutions on how to do these (with an answer at the end, etc). I might add some mroe Q's here as I find more quite simple aspects I fail to recall immediately.

Simplify 5 divide by X^2 + 2x
--- -------------
X - 2 x^2 - 4

Simplify 2m - n - m - 3n
--------- -----------
3 6

Solve simultaneously
4x - y = 9
3xy = -6

Find M in its simplest forn.
m = (√5 - √3)^2 + √60

Solvw (2X-1)(X+6) = 0

A copper sphere has a mass of 700g. Calculate the radius of the sphere given that 1cm^3 of copper has a mass of 8.95g.

Thanks for any help/tips, etc.

 

[watatank]

So we've done all these before, its just some I've forgotton how to do some, etc and woudl just like to see how to do one so that I can then practice with some similar ones. I'm not looking for answers, I'm looking for solutions on how to do these (with an answer at the end, etc). I might add some mroe Q's here as I find more quite simple aspects I fail to recall immediately.

Simplify 5 divide by X^2 + 2x
--- -------------
X - 2 x^2 - 4

Simplify 2m - n - m - 3n
--------- -----------
3 6

Solve simultaneously
4x - y = 9
3xy = -6

Find M in its simplest forn.
m = (√5 - √3)^2 + √60

Solvw (2X-1)(X+6) = 0

A copper sphere has a mass of 700g. Calculate the radius of the sphere given that 1cm^3 of copper has a mass of 8.95g.

Thanks for any help/tips, etc.

first: i'm not sure what you are asking in the first equation. the second part, you put it over a common denominator. hint: multiply the first term by 2/2


second: for the simultaneous equation theres a couple of ways you can do it. you can make y the subject in one equation and then sub that into the other equation and solve for x, then use that to solve y. you can also eliminate y by making it the subject of both equations and then solve for x by equating them.

third: i'd expand it out. √60 can also be simplified to √4 * √15 or simply 2√15

fourth one: think of it this way. if a * b = 0, then either a = 0, b = 0

fifth: if it weighs 700g, then the volume is 700/8.95 m³. so using (formula of a sphere) = 700/8.95, solve for r.

hope that helps. :wave: