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2 years ago

The sum of 2 numbers (x and y) is 20, and their product is 51. What are the values of x and y

Mathematics

1 answer:

Murljashka [212]2 years ago

4 0

Answer: 13&7

Step-by-step explanation:

The sum of two numbers x&y is 20

Product of the 2numbers xy is 51

X+y=20......equation 1

XY=51.........equation 2

X=20-y.......equation 3

Substitute for x inequation 3 into equation 2

So we have;

(20-y)y=51

Open the bracket

20y-y^2=51

Collect like terms,so we have

Y2-20y+51=0

Factorise

Factors of 51 is 13&7

So -13-7=-20 &-13×-7=51

Substitute

Y2-13y-7y+51=0

Y(y-13)-7(y-13)=0

(Y-7)(y-13)=0

Y-7=0

Y=7 or

Y-13=0

Y=13

Y=13 or 7

Substitute for y in equation 1

X+y=20

X+7=20

X=20-7

X=13 or

X+13=20

X=20-13

X=7

Therefore, X &Y = 13 &7

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2 years ago

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2 years ago

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2 years ago

Complete the solution of the equation. Find the

weeeeeb [17]

Answer: " y = -10 . "

___________________

Step-by-step explanation:

___________________

The question:

Find the value of "y" when "x" equals 17.

Given the equation:

- x + y = -27 ;

___________________

We plug in the given value: "17" ; for "x" ; and solve for "y" :

- 17 + y = -27 ;

_____________________

↔ y + (-17) = -27 ;

Rewrite as:

y − 17 = -27 ; {since: "adding a negative value" is the same

as "subtracting a positive value."}.

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Now, we add "17" to each side of the equation;

to isolate "y" on one side of the equation; and to solve for "y" :

y − 17 + 17 = -27 + 17 ;

to get:

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Hope this is helpful to you.

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7 0

2 years ago

Read 2 more answers

1. A luge race is very dangerous, and a crash can cause serious injuries. The league requires anyone who has a crash to have a t

antiseptic1488 [7]

Answer:

0.7061 = 70.61% probability she will have her first crash within the first 30 races she runs this season

Step-by-step explanation:

For each race, there are only two possible outcomes. Either the person has a crash, or the person does not. The probability of having a crash during a race is independent of whether there was a crash in any other race. This means that the binomial probability distribution is used to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

In which $C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

And p is the probability of X happening.

A certain performer has an independent .04 probability of a crash in each race.

This means that $p = 0.04$

a) What is the probability she will have her first crash within the first 30 races she runs this season

This is:

$P(X \geq 1) = 1 - P(X = 0)$

When $n = 30$

We have that:

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 0) = C_{30,0}.(0.04)^{0}.(0.96)^{30} = 0.2939$

$P(X \geq 1) = 1 - P(X = 0) = 1 - 0.2939 = 0.7061$

0.7061 = 70.61% probability she will have her first crash within the first 30 races she runs this season

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2 years ago