Xy = 50
x + y = 15
x = 15 - y
xy = 50
(5 - y)y = 50
5y - y^2 = 50
y^2 - 5y + 50 = 0
(y - 5)(y - 10) = 0
y - 5 = 0 or y - 10 = 0
y = 5 or y = 10
x + y = 15
For y = 5:
x + 5 = 15
x = 10
For y = 10
x + 10 = 15
x = 5
Answer: the numbers are 5 and 10.
F(x)=y=2x+3
P (1,5)
Substitute x and y:
5=2*(1)+3
5=5 true
Point P (1,5) is on the graph of f.
To solve for proportion we make use of the z statistic.
The procedure is to solve for the value of the z score and then locate for the
proportion using the standard distribution tables. The formula for z score is:
z = (X – μ) / σ
where X is the sample value, μ is the mean value and σ is
the standard deviation
when X = 70
z1 = (70 – 100) / 15 = -2
Using the standard distribution tables, proportion is P1
= 0.0228
when X = 130
z2 = (130 – 100) /15 = 2
Using the standard distribution tables, proportion is P2
= 0.9772
Therefore the proportion between X of 70 and 130 is:
P (70<X<130) = P2 – P1
P (70<X<130) = 0.9772 - 0.0228
P (70<X<130) = 0.9544
Therefore 0.9544 or 95.44% of the test takers scored
between 70 and 130.
Answer:
x = 1.25
Step-by-step explanation:
-3x+10 = 5x-8
+3x +3x
10 = 8x - 8
+8 +8
18 = 8x
x = 18/8
x = 1 1/4 = 1.25
