Answer:
Step-by-step explanation:
X^2+7x+63=63
<=> x^2+7x=63-63=0
<=> X(x+7)=0
<=> x1=0
X2=-7
Answer:
y-6
Step-by-step explanation:
Answer:
Step-by-step explanation:
z-score representing 85% is 1.04 (from table)
Let x be the score representing the lower limit of 85%.
<u>Use the formula to find z-scores:</u>
<u>We have:</u>
<u>Substitute the values and solve for x:</u>
- 1.04 = (x - 78)/7
- x - 78 = 7.28
- x = 85.28
The lower limit of the top 15% is 85.28.
Since your score is greater than 85.28 you earned an A
If we move 7 to one side, we have (y^2 + 4y -3) = 0. From this form, we can apply the quadrati formula to solve for the values of y.
To recall, quadratic formula is [ -b ±√ (b² - 4ac) ]/2a.
For our equation, we have a =1, b = 4, and c = -3. If we plug this in, we have y to have approximate values of -2 - sqrt(7) and -2 + sqrt(7)<span>.</span>
