✔ 最佳答案
hey!
Although these look really difficult, you need to tackle them one step at a time.
1) First look at the numbers in front, do they have a factor that goes into them?
15,20,35? yes, 5 is the biggest no that goes in.
so on the outside before brackets you put 5, since you will multiply with whats in the brakets.
2) Now, in all of the equations with letters appear?
they all have x and y only one equation has z so it doesnt go outside since no other equations have it.
BUT hold on, to save you time you can see that although these appear you can (square (^) ) them so its easier in the equation.which one can you do that to x (on the outisde)
here it the answer-
5x^2y(3x^2+4y^2z-7xy)
get it?? Try multiplying it out, it will be what you started with.
Using the method i just said try doing the other one
The answer is=
7xy^2(2xy+3-5x^2y^2)
You need the most 'common' thingys outside the brackets to make your life easier when multiplying with whats inside.
so if you include squares on the outside, which can appear inside aswel, then you can still manage to multiply.
REMEMBER-with indices when you MULTIPLY you ADD the powers so if on the outside it says,
x^3(x^3) You add them so its x^6
I hope it makes sense!!
:)