A student sketched some art on an 8 inch x 10 inch piece of paper. She wants to resize it to fit an 4 inch x 6 inch frame (as sh
own below). What percent of the original sketch was still able to be included in the frame?
1 answer:
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You have the right idea that things need to get multiplied.
What should be done is that the entire fraction needs to get multipled by the lowest common denominator of both denominators.
Let's look at the complex numerator. Its denominators are 5 and x + 6. Nothing is common with these, so both pieces are needed.
The complex denominator has x - 3 as its denominator. With nothing in common between it and the complex numerator, that piece is needed.
So we multiply the entire complex fraction by (5)(x + 6)(x -3).
Numerator:
= (x+6)(x-3) - (5)(5)(x-3)
= (x+6)(x-3) - 25(x-3)
= (x-3)(x + 6 - 25) <--- by group factoring the common x - 3
= (x -3)(x - 19)
Denominator:
Now we put the pieces together.
Our fraction simplies to (x - 3) (x - 19) / 125 (x + 6)
Answer:
see explanation
Step-by-step explanation:
Consider the left side
A +
A - 2cos²Asin²A ← is the expansion of
= (cos²A - sin²A)²
Substitute sin²A = 1 - cos²A
= (cos²A - (1 - cos²A) )²
= (cos²A - 1 + cos²A)²
= (2cos²A - 1 )²
= right side , then proven