2x+y = -5. Solve this for y. We get y = -2x - 5. Find y^2: 4x^2 + 20x + 25. Substitute 4x^2 + 20x + 25 for y^2 in the first equation:
x^2 + 4x^2 + 20x + 25 = 25
Then 5x^2 + 20x = 0, so that x = 0. Subst. 0 for x in the 2nd eqn and find the value of y. Write your solutions as shown above: ( , ) and ( , ).
Here are some very good video that explain how. very short and easy too. http://virtualnerd.com/pre-algebra/linear-functions-graphing/rate-of-change-slope/finding-slope/slop... math antics on youtube is great for help too
Step-by-step explanation:
1st expression= 6x^2y
2nd expression= 9xy
HCF= 3xy
Answer: a) 453 b) 1537
Step-by-step explanation:
As per given , we have
Margin of error : E= 0.025
Critical value for 95% confidence interval : 
a) The prior estimate of population proportion : p=0.08
Required sample size :-

The minimum sample size is 453 U.S. adults.
b) Since the prior estimate of population proportion is not available , so we take p= 0.5
Required sample size :-

The minimum sample size is 1537 U.S. adults.
0.405, 0.45 , 0.5 , 4.5 : Least to greatest!