A road is 4 cm long on the map. Find the actual length of the road.
1 answer:
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<h3>Answer: Choice D. </h3>
Morgan forgot to distribute the negative sign to two of the terms in the second expression.
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Explanation:
Focus on the numerators.
We have (3t^2-4t+1) as the first numerator and we subtract off (t^2+2t+2) as the second numerator.
Morgan needs to simplify (3t^2-4t+1)-(t^2+2t+2) for the numerator.
Mistakenly, she had these steps
(3t^2-4t+1)-(t^2+2t+2)
3t^2-4t+1-t^2+2t+2 .... her mistake made here
(3t^2-t^2)+(-4t+2t)+(1+2)
2t^2-2t+3
All of this applies to the numerator. The denominator stays at t+3 the entire time. So effectively we can ignore it on a temporary basis.
Here's what Morgan should have for her steps when simplifying the numerator.
(3t^2-4t+1)-(t^2+2t+2)
3t^2-4t+1-t^2-2t-2 ..... distribute the negative
(3t^2-t^2)+(-4t-2t)+(1-2)
2t^2-6t-1
Note in the second step, the negative outside flips the sign of each term in the second parenthesis.
Therefore,
which means
Side notes:
- The fractions can only be subtracted since the denominators are the same.
- We have
to avoid a division by zero error.
- Rational expressions are a fraction, or ratio, of two polynomials.
<h3>Answer: 2/3, -4/3</h3>
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Explanation:
You could use the AC method to factor this, but the quadratic formula is the most efficient route in my opinion. This will avoid any guess-and-check.
Compare the original equation to the form
We have a = 9, b = 6, and c = -8
Those values lead to...
Side notes:
- 2/3 = 0.667 approximately
- -4/3 = 1.333 approximately
- Since your teacher did not give rounding instructions, I'll assume s/he wants the fraction form of each x value (rather than the decimal form). Be sure to follow all instructions given, and ask for clarification if need.
- To confirm the solutions, replace every copy of x with either 2/3 or -4/3 (pick one value only). Simplifying the left hand side should lead to 0. I'll let you check each answer.