Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.
Trending News
A few algebra questions? Please help me out?
1. Which answer describes the restrictions for the variables?
x - 4/x + 1 (it's a fraction)
All the equal signs have a dash through them.
A) x = -4
B) x = 1
C) x = 4
D) x = -1
Is it a?
2. Which expression is in simplified form for the given expression in states the correct variable restriction?
u^2 - 2u / u^2 - 4 (It's a fraction)
All the equal signs have a dash through them.
A) u/u+2, u = -2
B) u-2/u+2, u = -2, and u = 2
C) 1/u+2, u = -2
D) u/u+2, u = -2, and u = 2
3. Multiply. Assume that no denominator equal zero.
9t^2/s multiplied by 5st^2/36
A) 5t^4/4
B) 5t^3/4
C) 5t^3/4s^2
D) 5t^4/9
1 Answer
- 5 years ago
1) Consider that it is a fraction, and that a denominator with a zero is undefined, so there is no answer, thus restricts the x value that would result in a zero. The denominator is x + 1. So the domain will be restricted when:
x + 1 = 0
Subtract 1 from both sides:
x = -1, So when x is negative one the denominator is zero, so no it is not A.
2) First we can simplify the expression by factoring both numerator and denominator. The numerator can factor out a u. The denominator is the difference of two squares so its' factors will appear in the form (a + b)(a - b).
(u^2 - 2u) / (u^2 - 4)
u(u - 2) / (u + 2)(u - 2)
We can see the numerator and the denominator have a common factor and thus will cancel each other. So the simplified form looks like:
u/(u + 2)
Next to consider restrictions again we seek to know the denominator is zero. If either (u + 2) or (u - 2) equals zero then the denominator will be zero so the function would be restricted at that point. So when does u + 2 = 0? When u = -2. And when does u - 2 = 0? When u = 2.
3) Well, The multiplication is simple enough: then just cancel/reduce like factors.
Multiplied we get ((45)(t^4)(s))/((36)(s))
One 's' in each the numerator and denominator so they cancel each other.
45/36 can be reduced to 5/4 so the final product is ((5)(t^4))/(4)