Question

need help.

Answer 1

http://prntscr.com/8ipx9a

Answer 2

@ganeshie8

Answer 3

the zero product property would say that you can set each equal to 0 then solve for x.

A you actually have wrong. It should be (x+45)(x-40)=0. this would give you the positive 5x in the equation.

(x+45)=0 and (x-40)=0

solve for x for both

x=-45 and x=40

C. This means that x could equal -45 and 40, and the equation would be true

you can plug the numbers in to check

x^2+5x-1800=0
(-45)^2+5(-45)-1800=0
2025-225-1800=0
1800-1800=0
0=0
this is a true statement.

40 should work as well if you plug it in

Answer 4

wait what do i write for b?

Answer 5

http://prntscr.com/8iq0hy

is this correct?

Answer 6

you showed it correctly, but used the wrong equation. your answer the A is wrong. My first reply explained why. you should end up with x=-45 and x=40

Answer 7

the equation for the length can be written as l=2w+10, where w is the width.since the width can't be a negative number, it has to be 40. so the length can be found by plugging 40 into w.

l=2w+10
l=2(40)+10
l=80+10
l=90

Answer 8

and you know this is correct because the total area of the dog park is 3600.
area=lxw
you now know the length is 90 and the width is 40
90X40=3600

which is true