andriod09 3 years ago Factor trinominal times a binomial equation in the comments

1. andriod09

$\left( 2x+4y+7 \right)\left( 5x+8 \right)$

2. andriod09

@ganeshie8

3. ganeshie8

is it 'factor' or 'multiply' ?

4. andriod09

you have to factor it. but its presented as a multiplication question.

5. ganeshie8

hmm interesting.. its already in factored form i guess we cant factor it any further

6. andriod09

i think it might be multiplying it though. the question is: 7.How about multiplying a trinomial times a binomial?

7. ganeshie8

yea this makes sense :)

8. ganeshie8

just have to multiply..

9. ganeshie8

you familiar wid multuplying these right ?

10. andriod09

somewhat

11. ganeshie8

$$(2x+4y+7)(5x+8)$$ $$(\color{green}{2x}+4y+7)(\color{green}{5x+8})$$

12. ganeshie8

first distribute 2x

13. ganeshie8

then 4y and lastly 7

14. andriod09

in between them, would i use ()+()+() or just ()()()?

15. ganeshie8

thats right ! in between we add. () + () + ()

16. ganeshie8

$$(\color{green}{2x}+4y+7)(\color{green}{5x+8})$$ $$10x^2 + 16x + 20xy + 32y + 35x + 56$$

17. ganeshie8

see if above makes sense

18. andriod09

$\left( 10x^{2}+16x \right)+\left( 20xy+24y \right)+\left( 35x+56? \right)$

19. ganeshie8

thats almost right !! except for $$24y$$

20. andriod09

i mistyped it. lool. its (20xy+32)

21. ganeshie8

right ! now remove ()

22. ganeshie8

and see if any like terms are there

23. andriod09

16x and 35x and thats it.

24. ganeshie8

yup :)

25. ganeshie8

add them and write it in order

26. andriod09

$(10x^{2}+51x+20xy+24y+56)$

27. ganeshie8

$$\left( 10x^{2}+16x \right)+\left( 20xy+32y \right)+\left( 35x+56? \right)$$ $$10x^{2}+16x +20xy+32y +35x+56$$ $$10x^{2}+20xy +51x+32y + 56$$

28. ganeshie8

again 24y. ...

29. ganeshie8

if we ignore that 24y mistype, your final polynomial looks good except for one thing

30. andriod09

$(10x^{2}+51x+20xy+32y+56)$

31. ganeshie8

20xy order is more

32. ganeshie8

so you have to move it to left,

33. ganeshie8

and 51x to right.. swap 20xy and 51x