d) You have a <u>difference of squares</u>:
49y² - 9 = (7y)² - 3²
Recall the identity,
a² - b² = (a - b) (a + b)
So,
49y² - 9 = (7y - 3) (7y + 3)
e) Pull out the common factor 3 from each term:
3x² - 3x - 90 = 3 (x² - x - 30)
Now use the <u>sum-product method</u>. Notice that we can write 30 = 5 • 6, and 5 - 6 = 1, so
3x² - 3x - 90 = 3 (x + 5) (x - 6)
f) Same as in (e), use the <u>sum-product method</u>. Notice that 42 = 7 • 6, and -7 - 6 = -13, so
x² - 13x + 42 = (x - 7) (x - 6)
Answer: BC = 15
Step-by-step explanation:
Since the triangles are congruent, that means they are the same. So side AB = side EF. Since we know side FD is 15, that means side BC= 15
Number 16- 216
number 17- 180
number 18- 252
Answer:
40 seconds
Step-by-step explanation:
The ratio would be 3:120, indicating the amount of times it went up for air in 120 seconds. In order to find the answer, we'll find the unit rate. 120 divided by 3 is evenly 40. That means, the unit rate is 1:40. It also means that 40 seconds went by before the manatee surfaced the first time (if it held its breath for the same rate).
Answer:
120
Step-by-step explanation:
The absolute value is 120. Think about it on a number line, the absolute value is the amount of spaces that -120 is away from 0. Therefore, the amount of spaces -120 is from 0, is 120.
