these are the answers ( i just did this and got it right)
1) Ionic radii tend to increase down a group.
4) Cationic radii tend to decrease across a period.
5) Ionic radii increase when switching from cations to anions in a period.
Answer:
15x + 180 ≥ 900
x ≥ 48
Step-by-step explanation:
x = amount of laptops needed to sell.
Equation:
15x + 180 ≥ 900
15x ≥ 720
x ≥ 48
Check:
15(48) + 180 = 900
720 + 180 = 900
900 = 900 (It's good, she needs to make at least 900, so she needs to sell at least 48 laptops).
Answer:
Step-by-step explanation:
Find the sum of the first 42 terms of the following series, to the nearest integer.
2,7,12
Solution
The sum is given by
SUM_n=n/2*(a_1+a_n)
a_n=a_1+(n-1)d
a_1=2, n=42, d=5
The 42nd term is therefore given by
a_42=2+(42-1)5=207
SUM_42=42/2*(2+207)=21*209=4389
The sum of the first 42 terms of the series, therefore, is 4389
Answer:
9
Step-by-step explanation:
the answer is 9 because 7 goes into 63 evenly 9 times