Answer:
x=8
Step-by-step explanation:
2x+9=3x+1
-3 -3
-9 -9
-1x=-8
divide both side by -1.
x=8
A for the first one and D for the second
Answer:
mary=10 jack=15
Step-by-step explanation:
After 4 years Mary (x+4), Jack's age (x+5) + 4.
sum of the ages after 4 years :(x+4) + (x+5) +4=33
Simplifying the equation:
2x+13 = 33 ----->> 2x=20----->>>>x = 10 Mary's age
10 + 5 = 15 which is Jack's age.
The standard deviation of the set is 5.2
To find standard deviation, we take the square root of the variance.
50% is

We have two ways to do this, pick your favor:
either by fractions:

÷

(

Multiply by the reciprocal of

which is 2(flip it)

× 2 =
= 1.25
Or change them to decimals:


= 0.5
0.625 ÷ 0.5
0.5 I 0.625
multiply by 10 to make it easier to divide(it still gives us the same answer)
0.5 × 10 = 5
0.625 × 10 = 6.25
1.25
5 I 6.25
-5
12
-10
25
-25
0
0.625 ÷ 0.5 =
1.25