Answer:
A) -84x^3 - 8x
B) -91x^4 + 143x^2 - 65x
C) 12b^2 - 7b - 10.
D) 16x^2 - 72x + 81
Step-by-step explanation:
A) -4x(21x^2-3x+2)
B) -13x(7x^3-11x+5)
C) (3b+2)(4b-5)
D) (4x-9)^2
In A) -4x(21x^2-3x+2) we are multiplying the binomial (21x^2-3x+2) by the monomial -4x; there are two multiplications involved:
-4x(21x^2) = -84x^3
and
-4x(-3x+2) = +12x^2 - 8x.
Hence A) -4x(21x^2-3x+2) = -84x^3 - 8x
B) The work done to find the product in B) is similar: Multiply each term in 7x^3-11x+5 by -13x:
The end result is -91x^4 + 143x^2 - 65x
C) Here we are multiplying together two binomials; we use the FOIL method: Multiply together the First terms, then the Outer terms, then the Inner terms, and finally the Last terms. This results in:
(3b+2)(4b-5) = 12b^2 -15b + 8b -10, or, after simplification, 12b^2 - 7b - 10.
In D) we are squaring a binomial. The formula for this is:
(a - b)^2 = a^2 - 2ab + b^2. Here,
(4x - 9)^2 = 16x^2 - 2(36x) + 81, or 16x^2 - 72x + 81
If you take 46.59 and subtract 43.8 you get 2.79. Therefore 2.79 is your answer.
Answer:
The third choice: -4, 0, and 1
Step-by-step explanation:
Finding zeroes is another way of saying solve...set the equation equal to zero and solve..
0 = 2x³ + 6x² - 8x
0 = 2x(x² + 3x - 4) (factor out a 2x from all three terms)
0 = 2x(x + 4)(x - 1) (factor x² + 3x - 4)
So
2x = 0 then x = 0
x + 4 = 0 then x = -4
x - 1 = 0 then x = 1
Our zeroes are -4, 0, and 1
1. 3a - 1 + 18 - a
So you can reorder these, as long as they keep the sign in front of them.
3a - a - 1 + 18, you can reorder it to.
And then just add or subtract.
2a + 17
2. (a+3) - (a + 2)
First you want to open the parenthesis.
To do that, check the symbol before the parenthesis.
If it's a minus, reverse the operator inside the parenthesis. If it's a plus, do nothing.
So just,
a + 3 - a - 2
Then reorder again
a - a + 3 - 2
1
3. 43 + a - 2a
Just subtract, a - 2a, to get -a.
So,
43 - a
