Mathematics: If x + 4y = 18 and x - 4y = 2, then x =? a) 2 b) 4 c) 5 d)10

If x + 4y = 18 and x - 4y = 2, then x =? a) 2 b)

Lydiaxqueen

12.01.2022

The Final answer is option D ) 10

x=10

Step-by-step explanation:

Given:

x + 4y = 18 ......................Equation( 1 )

x - 4y = 2 ......................Equation( 2 )

To Find:

x =?

Solution:

Adding Equation ( 1 ) and ( 2 ) we get

$x+4y+x-4y=18+2\\\\2x=20\\\\\therefore x =\frac{20}{10} \\\\\therefore x =10$

The Final answer is option D ) 10

0,0(0 оценок)

kim643

02.08.2020

The coach should start recruiting players with weight 269.55 pounds or more.

Step-by-step explanation:

We are given the following information in the question:

Mean, μ = 225 pounds

Standard Deviation, σ = 43 pounds

We are given that the distribution of weights is a bell shaped distribution that is a normal distribution.

Formula:

$z_{score} = \displaystyle\frac{x-\mu}{\sigma}$

We have to find the value of x such that the probability is 0.15

$P( X x) = P( z \displaystyle\frac{x - 225}{43})=0.15$

$= 1 -P( z \leq \displaystyle\frac{x - 225}{43})=0.15$

$=P( z \leq \displaystyle\frac{x - 225}{43})=0.85$

Calculation the value from standard normal z table, we have,

P(z < 1.036) = 0.85

$\displaystyle\frac{x - 225}{43} = 1.036\\\\x = 269.548 \approx 269.55$

Thus, the coach should start recruiting players with weight 269.55 pounds or more.

0,0(0 оценок)