Can someone really help me I don't understand this

1. a=1 b=9 c=20

(x+5) (x+20)

2. a=1 b=2 c=-8

(x-2)(x+4)

Step-by-step explanation:

When you use the box method, follow these steps (only usable when a=1)

(i'll be using x^2+9x+20 as an example)

be sure to understand that the formula is ax^2+bx+c

1. the top left corner is a, so put x^2

2. the bottom right is the c, or the y intercept. that would be 20 when using x^2+9x+20

3. find 2 numbers that when multiplied equal c and when added equal b. in this problem, 4(5)=20 and 4+5=9, so 4 and 5 belong in the remaining 2 boxes. make sure to add the x after each term, since these terms are b.

4. find to common term in each row of the box (x^2 and 4x share x, and 5 and 20 share 5) and then the common terms in the columns (x^2 and 5x share x and 4 and 20 share 4)

this should give you (x+4)(x+5)

hope this helps!

the 3rd option is right

step-by-step explanation: