Answer:
-3 + 8a
Step-by-step explanation:
multiply 3 by -1 as well as -8a by -1 and you'll get -3 + 8a
Answer:
C. In 2001, the temperature was 83°F.
Step-by-step explanation:
79 is 4 less than 83.
The temperature in 2001 was 83 °F.
Five years ago:
Peter= P-5
Sam = S-5
Peter was 3 times older than Sam, which means that (P-5) = 3(S-5)
P-5 = 3S-15
So, the equation that would complete the system is C. P - 5 = 3S - 15
P-5 = 3S-15
P-3S = -15+5
P-3S = -10
So, now we use two equations: P-3S = -10 and the original one P+S=30
P-3S=-10
P+S=30 (to simplify the equation, multiply it by -1)
P-3S=-10
-P-S=-30
__________
0P-4S=-40
-4S=-40
4S=40
S=40/4
S=10
P+S=30
P+10=30
P=20
This means that Pete is 20, and Sam is 10. Hope this helps!
Ok so the answer is super simple, its A
Answer: 0.8238
Step-by-step explanation:
Given : Scores on a certain intelligence test for children between ages 13 and 15 years are approximately normally distributed with 
and 
.
Let x denotes the scores on a certain intelligence test for children between ages 13 and 15 years.
Then, the proportion of children aged 13 to 15 years old have scores on this test above 92 will be :-
![P(x>92)=1-P(x\leq92)\\\\=1-P(\dfrac{x-\mu}{\sigma}\leq\dfrac{92-106}{15})\\\\=1-P(z\leq })\\\\=1-P(z\leq-0.93)=1-(1-P(z\leq0.93))\ \ [\because\ P(Z\leq -z)=1-P(Z\leq z)]\\\\=P(z\leq0.93)=0.8238\ \ [\text{By using z-value table.}]](https://tex.z-dn.net/?f=P%28x%3E92%29%3D1-P%28x%5Cleq92%29%5C%5C%5C%5C%3D1-P%28%5Cdfrac%7Bx-%5Cmu%7D%7B%5Csigma%7D%5Cleq%5Cdfrac%7B92-106%7D%7B15%7D%29%5C%5C%5C%5C%3D1-P%28z%5Cleq%20%7D%29%5C%5C%5C%5C%3D1-P%28z%5Cleq-0.93%29%3D1-%281-P%28z%5Cleq0.93%29%29%5C%20%5C%20%5B%5Cbecause%5C%20P%28Z%5Cleq%20-z%29%3D1-P%28Z%5Cleq%20z%29%5D%5C%5C%5C%5C%3DP%28z%5Cleq0.93%29%3D0.8238%5C%20%5C%20%5B%5Ctext%7BBy%20using%20z-value%20table.%7D%5D)
Hence, the proportion of children aged 13 to 15 years old have scores on this test above 92 = 0.8238
