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Algebraic Manipulation - Quiz 3   Last unanswered question  Question  Next unanswered question

Question 1 lion

Which of the following correctly makes  y   the subject of  3x - 2y+ 5 = 0?
a) 5+-3x- y = 2 .   b) y = 5 + 3x . 2
c) 3 y = 5- - x. 2   d) 5+ 2x y = --3---.

 

Your answer is correct.
Add  2y   to both sides of the equation and  3x + 5 = 2y   then
y = 3x+-5-. 2
Not correct. Choice (b) is false.
Try again, you haven’t performed the operations in the right order, watch the signs.
Not correct. Choice (c) is false.
Try again, you haven’t performed the operations in the right order.
Not correct. Choice (d) is false.
Try again, you have confused the coefficients of   x   and   y.
Question 2 lion

Is the following factorized fully?

      2x2y- 4xy2 + 6xy = 2y(x2 - 2xy +3x) .
a) True.   b) False.

 

Not correct. Choice (a) is false.
Try again, this is not factorized fully.
Your answer is correct.
This is not factorized fully.
      2x2y - 4xy2 + 6xy = 2y(x2 - 2xy + 3x) = 2xy(x - 2y + 3).
Question 3 lion

Which of the following are fully factorized?
There may be more than one correct answer.
a) 2 2 3 2 4mn - 2m n = 2mn (2 - mn) .
b) 23 32 2 2 - 2a b - 5a b = - a b (2b - 5a).
c) 2 6b xc- 2bc+ 4bcd = 2bc(3bx - 1+ 2d).
d) 2 2 2 2 9p q r+ 3p qr = 3p qr(3q +1) .
e) 2 2 ab+ a b - ab = ab(1 - a + b).

 

There is at least one mistake.
For example, choice (a) should be true.
There is at least one mistake.
For example, choice (b) should be false.
2 3 32 2 2 - 2a b - 5a b = - a b (2b+ 5a).
There is at least one mistake.
For example, choice (c) should be true.
There is at least one mistake.
For example, choice (d) should be true.
There is at least one mistake.
For example, choice (e) should be false.
2 2 ab+ a b- ab = ab(1+ a- b).
Your answers are correct
  1. True.
  2. False. 2 3 32 2 2 - 2a b - 5a b = - a b (2b+ 5a).
  3. True.
  4. True.
  5. False. 2 2 ab+ a b- ab = ab(1+ a- b).
Question 4 lion

Which of the following correctly makes  σ   the subject of   x--μ- z = √σ- ? n
a) x- μ σ = --z--.   b) zμ- x σ = -√n---.
c) (x- μ)√n-- σ = ----z----.   d) x-√-- σ = z n - μ.

 

Not correct. Choice (a) is false.
Try again, you have forgotten  √ -- n,.
Not correct. Choice (b) is false.
Try again, multiply both sides by  σ √n-.
Your answer is correct.
Multiply both sides by  -σ- √n--   and
-σ- z√n--= x- μ   so  -σ- x-- μ √n--= z   and
    √ -- (x--μ)--n σ = z .
Not correct. Choice (d) is false.
Try again, multiply both sides by  σ-- √n-.
Question 5 lion

Which of the following makes  n   the subject of the formula   x--μ- t = √s- ? n
a) (x - μ)2 n = -st-- .   b) ( st )2 n = x-- μ .
c) n = ---st---. (x- μ)2   d) n = --st2--. x2 - μ2

 

Not correct. Choice (a) is false.
Try again, you have found  1 n-. .
Your answer is correct.
If   x- μ t = -√s-- n   then  (x - μ)√n- t = --------- s   and
√n--= -st--, x- μ   hence
    ( )2 n = -st-- . x- μ
Not correct. Choice (c) is false.
Try again, you have not dealt with the square root sign correctly.
Not correct. Choice (d) is false.
Try again, you have not dealt with the square root sign correctly.