Question

What is the expression in factored form?

-x^2 + 3x + 28

a. (x-7)(x-4)
b. -(x-7)(x+4)
c. (x+4)(x+7)
d. -(x-4)(x+7)

Answer 1

Answer:

$\boxed{b.\:\:-(x-7)(x+4)}$

Step-by-step explanation:

The given expression is $-x^2+3x+28$

We split the middle term to obtain;

$-x^2+7x-4x+28$

We factor to get;

$-x(x-7)-4(x-7)$

We factor further to obtain;

$=(x-7)(-x-4)$

We factor the negative 1 to get;

$=-(x-7)(x+4)$

Answer 2

Answer:

Choice b is correct answer.

Step-by-step explanation:

Given expression is:

-x²+3x+28

We have to represent above expression in factored form.

Split the middle term of given expression so that the product of two terms should be -28 and their sum be 3.

-x²+7x-4x+28

make two groups and taking common,we get

-x(x-7)-4(x-7)

taking (x-7) as common,we get

(x-7)(-x-4)

As we observed that -1 is common in last term of above expression.

take negative sign as common

-(x-7)(x+4)  which is the answer we required.