Evaluate -3x2 - 4x for x= -1. need help please. the answers are either 7. -1. 1.

1 hope it helps if not sorry

Step-by-step explanation:

A. Factor1. Factor 3x2 + 6x if possible.

Look for monomial (single-term) factors first; 3 is a factor of both 3x2

and 6x and so is x . Factor them out to get

3x2 + 6x = 3(x2 + 2x1 = 3x(x+ 2) .

2. Factor x2 + x - 6 if possible.

Here we have no common monomial factors. To get the x2 term

we'll have the form (x +-)(x +-) . Since

(x+A)(x+B) = x2 + (A+B)x + AB ,

we need two numbers A and B whose sum is 1 and whose product is

-6 . Integer possibilities that will give a product of -6 are

-6 and 1, 6 and -1, -3 and 2, 3 and -2.

The only pair whose sum is 1 is (3 and -2) , so the factorization is

x2 + x - 6 = (x+3)(x-2) .

3. Factor 4x2 - 3x - 10 if possible.

Because of the 4x2 term the factored form wli be either

(4x+A)(x +B) or (2x+A)(2x+B) . Because of the -10 the integer possibilities for the pair A, B are

10 and -1 , -10 and 1 , 5 and -2 . -5 and 2 , plus each of

these in reversed order.

Check the various possibilities by trial and error. It may help to write

out the expansions

(4x + A)(x+ B) = 4x2 + (4B+A)x + A8

1 trying to get -3 here

(2x+A)(2x+B) = 4x2 + (2B+ 2A)x + AB

Trial and error gives the factorization 4x2 - 3x - 10 - (4x+5)(x- 2) .

4. Difference of two squares. Since (A + B)(A - B) = - B~ , any

expression of the form A' - B' can be factored. Note that A and B

might be anything at all.

Examples: 9x2 - 16 = (3x1' - 4' = (3x +4)(3x - 4)

x2 - 29 = x2 - (my)* = (x+ JTy)(x- my)

1

Step-by-step explanation:

Put x=-1 into the equation we get -3 + 4 = 1

.19875994384

step-by-step explanation:

1699/ 8548

(b) 240

step-by-step explanation:

first, we use the pythagorean formula using the given side lengths to find x. then we use x to find the side lengths. then we add the side lengths to find the perimeter.

pythagorean theorem formula:

a^2 + b^2 = c^2

(x - 20)^2 + (x - 40)^2 = x^2

x^2 - 40x + 400 + x^2 - 80x + 1600 = x^2

x^2 -120x + 2000 = 0

(x - 100)(x - 20) = 0

x - 100 = 0 or x - 20 = 0

x = 100 or x = 20

we see that the solution x = 20 must be discarded because it will give a negative side length and a side length of 0. the only valid solution is x = 100.

perimeter = sum of the lengths of the sides

perimeter = x + x - 20 + x - 40

perimeter = 3x - 60

replace x with 100.

perimeter = 3(100) - 60

perimeter = 300 - 60

perimeter = 240