What is the correct way of saying ?

Question

A/(x + 1) + B/(x - 1) = y → [A(x - 1) + B(x + 1)] /[(x + 1)(x - 1)] = y

can I say: "do the LCD at (the)left side" or "find the LCD at (the)left side"? The article (the) is needed?

and, moreover, how do you say about:

(x - 1)(x + 2)/(x - 1) = x + 2 ?

Is it right say: "I cancel out (x- 1)" or "(x - 1) is canceled out" ?

and finally:

sin(x) + cos(x) if I replace x with pi/2, can I say "plug in pi/2" or rather

"plug pi/2 into the expression" and which is better plug "in" or plug "into"?

P.S. √(4a - 4b) → 2 √(a - b) do you say: "factor out 4 from the sqrt" or

"factor 4 out of the sqrt" ? (the latter sounds better, I believe..)

Thanks in advance!!

Answer 1

get the LCD of this equation A/(x + 1) + B/(x - 1) = y and it would result to [A(x - 1) + B(x + 1)] /[(x + 1)(x - 1)] = y

(x - 1)(x + 2)/(x - 1) = x + 2

(x-1) would be canceled because it is found in the numerator and the denominator which would result to (x+2)=(x+2)

sin(x) + cos(x)

it is better to say it as x is equal to pi/2 because they would think that pi/2 is a substitute for x

√(4a - 4b)

factor the square root of the open parenthesis of 4a-4b close parenthesis which would result to √(4)(a - b) by collecting the 4 and the final answer is 2 √(a - b) by getting the square root of 4 it would become 2 that is outside of the radical sign.

your welcome