9 and 3. Because 9 is a composite number (3*3 = 9) and 3 is a composite number (1*3 = 3).
Answer:
A simple way to mentally subtract is to simplify the numbers, subtract, then subtract or add for the simplified answer.
Step-by-step explanation:
A simple way to mentally subtract is to simplify the numbers, subtract, then subtract or add for the simplified answer. For this 304 - 81 is easier as 300 - 80. Make note that we took away 4 from 304 and 1 from 81. Now we just subtract mentally, and 300 - 80 = 220. If we took 4 from 304, this means that our answer should be 4 less, since 4 less would be 304 - 80 = 216. If we took 1 from 81, then we add 1 back to get the equation 304 - 81 = 217.
304 - 81 = ?
300 - 80 = 220
304 - 80 = 216
304 - 81 = 217
Answer:
The inverse is 1/2x -3/2
Step-by-step explanation:
y =2x+3
Exchange x and y
x = 2y+3
Solve for y, subtracting 3 from each side
x-3 = 2y+3-3
x-3 =2y
Divide each side by 2
(x-3)/2 = 2y/2
1/2x - 3/2 =y
The inverse is 1/2x -3/2
Answer:
95% confidence interval for the difference between the average mass of eggs in small and large nest is between a lower limit of 0.81 and an upper limit of 2.39.
Step-by-step explanation:
Confidence interval is given by mean +/- margin of error (E)
Eggs from small nest
Sample size (n1) = 60
Mean = 37.2
Sample variance = 24.7
Eggs from large nest
Sample size (n2) = 159
Mean = 35.6
Sample variance = 39
Pooled variance = [(60-1)24.7 + (159-1)39] ÷ (60+159-2) = 7619.3 ÷ 217 = 35.11
Standard deviation = sqrt(pooled variance) = sqrt(35.11) = 5.93
Difference in mean = 37.2 - 35.6 = 1.6
Degree of freedom = n1+n2 - 2 = 60+159-2 = 217
Confidence level = 95%
Critical value (t) corresponding to 217 degrees of freedom and 95% confidence level is 1.97132
E = t×sd/√(n1+n2) = 1.97132×5.93/√219 = 0.79
Lower limit = mean - E = 1.6 - 0.79 = 0.81
Upper limit = mean + E = 1.6 + 0.79 = 2.39
95% confidence interval for the difference in average mass is (0.81, 2.39)
Answer:
Shorter leg = 2.5 ft.
Longer leg = 6.5 ft.
Step-by-step explanation:
a^2 + b^2 = c^2
Because the hypotenuse = 7 ft, a^2 + b^2 = 49
To represent the two legs, we can use x and x+4.
x^2 + (x+4)^2 = 49
Simplifying this equation using FOIL gives us 2x^2 + 8x - 33 = 0.
Then, using the quadratic formula, we find that x = 2.5.
Thus, the shorter leg is 2.5 ft. and, when 4 is added, the longer leg is 6.5 ft.
