midnightadd midnightadd
  • 24-02-2021
  • Mathematics
contestada

Solve using the substitution method. 3x +2y= 19 xy= 15​

Respuesta :

Adetunmbiadekunle Adetunmbiadekunle
  • 01-03-2021

Answer:

when x = 3 1/3, y = 4.5

or

when x =3 , y = 5

Step-by-step explanation:

Here, we want to solve using substitution

xy = 15

let x = 15/y

Put this into the first equation;

3(15/y) + 2y = 19

45/y + 2y = 19

Multiply through by y

45 + 2y^2 = 19y

2y^2 -19y + 45 = 0

2y^2 - 10y - 9y + 45 = 0

2y(y-5) -9(y-5) = 0

(2y-9)(y-5) = 0

2y-9 = 0

or y-5 = 0

2y = 9 or y = 5

y = 9/2 or y = 5

y = 4.5 or y = 5

Recall;

x = 15/y

x = 15/4.5 or x = 15/5

x = 3 1/3 or x = 3

Answer Link

Otras preguntas

studying genes and inheritance is it science or pseudoscience
Write 12,430,090in expanded form
A coordinate adjective is
Jacob earned $80 babysitting and deposited the money into his savings account. The next week he spent $85 on video games. Use integers to describe the weekly c
If I have a picosecond laser how would that be expressed in terms of zeptoseconds? In terms of petaseconds?
what is 1/10 of 7000?
A 1,000-kilogram car traveling with a velocity of +20. meters per second decelerates uniformly at -5.0 meters per second squared until it comes to rest. What i
show your work for 12.6 divided by 0.6
What is chattel slavery
A common trait in the rise to power of Hitler and Mussolini was that they both a. ended unemployment b. universally eliminated all other political parties c.