Let the missing number be x
Mean is the total sum of data over the number of data therefore,
(11+20+x+3+1) / 5 = 9
Then simplify
(35 + x) / 5 = 9
Then multiply 5 to both sides
35 + x = 45
Then subtract 35 to both sides to find x
X= 10
Hope this helps!
Oldest = 2x
Middle = x + 5
Youngest = x
2x + x + 5 + x = 57
combine like terms
4x + 5 = 57
subtract 5 from both sides
4x = 52
divide both sides by 4 to isolate x
x = 13
Oldest = 2x = 2(13) = 26
Middle = x + 5 = 13 + 5 = 18
Youngest = x = 13
Answer:
C
Step-by-step explanation:
An equation is where you already have the answer but you have to find out what the variable is to prove that the equation is true.
Answer: y = 0.5, x = 50
Step-by-step explanation: Both triangles in the picture are isosceles, telling us that the 2 angles at the bottom are congruent. With this, we can find y by doing the following:
a triangle has 180 degrees so we subtract the given 50 which gives us 130
2(2y + 64) = 130
4y + 128 = 130
y = .5
This means that the bottom 2 angles are both 65. Since the top angle of the second triangle is supplementary to the bottom angle of the first one, the top angle of the second triangle is 115. So, we find x by:
2(45 - x/4) = 65
x = 50
This means the bottom 2 angles of the second triangle are both 32.5.