Answer:
The common difference is 2
Step-by-step explanation:
The formula for an arithmetic sequence is
an = a1+d(n-1)
a1 = -5
a10 = 13
Substituting n=10 a10=13 and a1 =-5
13 = -5 +d (10-1)
13 = -5 +9d
Add 5 to each side
13+5 = -5+5 +9d
18 = 9d
Divide each side by 9
18/9 = 9d/9
2 =d
The first thing you want to do is plug in x and y into both equations:
a(3) + b(4) = 4
b(3) + a(4) = 8
rearrange to line up a’s and b’s
3a + 4b = 4
4a + 3b = 8
now you want to choose a or b and multiply each equation by a number to make them have the same amount of a’s or b’s.
4(3a + 4b = 4) = 12a + 16b = 16
3(4a + 3b = 8) = 12a + 9b = 24
Now we subtract the bottom equation from the top and solve for b:
12a + 16b - (12a + 9b) = 16 - 24
7b = -8
b = -8/7
Now we plug back in for b to one of the original equations:
3a + 4(-8/7) = 4
3a + (-32/7) = 4
3a - (32/7) = 4
3a = 4 + (32/7)
3a = (28/7) + (32/7)
3a = 60/7
a = (60/7)/3 = 20/7.
Finally, plug a and b in together to double check using the second equation.
4a + 3b = 8
4(20/7) + 3(-8/7) = ?
(80/7) - (24/7) = ?
56/7 = 8.
-22 = -2x + 9
-31 = -2x
-31/-2 = x
x = 15.5
Answer:
Answer to first question is:
You can convert all fractions to decimals. The decimal forms of rational numbers either end or repeat a pattern. If the fraction is a mixed number, change it to an improper fraction. Divide the numerator by the denominator. If the division doesn't come out evenly, round the decimal off.
Answer to second question is: 0.222222
Answer to third question is: Yes
Step-by-step explanation:
Well the way I think of it is:
3/9 as a fraction is 1/3... so 1 divided by 3 equals 0.333333 repeating. You can even write it as:
_
0.3 with the fraction bar over it because it keeps repeating.
This goes for 2/9. All you have to do is do 2 divided by 9 and you get 0.222222 repeating. You can even write it as:
<h3>
_</h3>
0.2 with the fraction bar over it because it keeps repeating.
Hope this helps, have a good day. c;