Help me please

[MikeD]

I apologize in advance if my question has been asked before, but I can't seem to find it.

Can anyone tell me the technique or formula to solve the following:

(y+4)(y-3)+(y-2)(y-3)

this was taken from my math textbook, but I cannot get the answer the back of the book has provided.= 18-2y^2-4y-6

If anyone could help me with this, it would be greatly appreciated

thank you

 

[Guest]

(y+4)(y-3)+(y-2)(y-3)

expand each part one at a time
(y+4)(y-3) = y^2 -3y + 4y - 12

do the same for the second part and then add to gether.

Have a go and we can work through it.

 

[MikeD]

Thank you very much, I have succesfully solved this problem.

You've explained it very clearly, and replied much quicker than I had expected.

Thank you once again

 

[Denis]

(y+4)(y-3)+(y-2)(y-3)
this was taken from my math textbook, but I cannot get the answer the back of the book has provided.= 18-2y^2-4y-6

If book gives that answer, then it's wrong;
answer is 2y^2 - 4y - 6 , or 2(y^2 - 2y - 3).

You can take a shortcut, since (y - 3) is common to both:
(y - 3)(y + 4 + y - 2)
=(y - 3)(2y + 2)
= 2y^2 + 2y - 6y -6
= 2y^2 - 4y - 6
Only one multiplication.