Which first step for solving the given system using substitution results in an equation without fractions?

Mathematics

1 answer:

Alexeev081 [22]3 years ago

3 0

Answer:

The step to take to avoid fraction is to solve for y in equation 2

Step-by-step explanation:

Given

-9x+ 4y =- 10

-9x+ 3y = 3

Required:

Step for solving using substitution (avoiding fraction)

Let -9x+ 4y =- 10 represent equation 1

and -9x+ 3y = 3 represent equation 2

The following points are to be noted

Solving for x or y in equation 1 will definitely lead to having fractions

Solving for x in equation 2 will also lead to having fractions

Having said that, the step to take to avoid fraction is to solve for y in equation 2

Check

$-9x+ 3y = 3$

Add 9x to both sides

$9x-9x+ 3y = 3 + 9x$

$3y = 3 + 9x$

Divide through by 3

$\frac{3y}{3} = \frac{3 + 9x}{3}$

$y = \frac{3 + 9x}{3}$

Split fraction

$y = \frac{3}{3} + \frac{9x}{3}$

$y = 1 + 3x$

At the point, the expression of y can then be substituted in equation 1

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There is a 0.9986 probability that a randomly selected 33-year-old male lives through the year. A life insurance company charge

Helen [10]

Answer:

Expected Value = -$42 (loss of 42 dollars)

Step-by-step explanation:

Complete Question Below:

"There is a 0.9986 probability that a randomly selected 33-year-old male lives through the year. A life insurance company charges $182 for insuring that the male will live through the year. If the male does not survive the year, the policy pays out $110 comma 000 as a death benefit. If a 33-year-old male purchases the policy, what is his expected value?"

We can say P(survival) = 0.9986 and thus P(not survival) = 1 - P(survival) = 1-0.9986 = 0.0014

Also,

In case 33 year old doesn't live, the payment would be 100,000 - 182 = $99,818

And

In case 33 year old lives, the payment is

-$182

We know, the expected value is the sum of the product of each possibility with its probability.

$ExpectedValue=\Sigma x*p(x)=(99818)(0.0014)+(-182)(0.9986)=-42$