00053254
00053254 00053254
  • 08-05-2020
  • Mathematics
contestada

what is the solution to X and Y in these equations 3x + 9y=60 and -3x + y=30

Respuesta :

peace7316
peace7316 peace7316
  • 08-05-2020

Answer:

x= -7 and y = 9

Step-by-step explanation:

multiply equation 1 by 1 which is the coefficient of y in the 2nd equa and equation 2 by 9 which is the coefficient of the first equation that will give:

3x + 9 = 60

-27x + 9y = 270

then add the two together that will give:

-27x - 3x +9y -9y = 270- 60

-30x=210

x= -7

substitute x for -7 in equation 1

3(-7)+9y=60

-21+9y= 60

9y=60+21

9y=81

divide both sides by 9

that will give the answer 9

so x= -7 and y = 9

Answer Link

Otras preguntas

Why should I represent my school? ASAP PLEASE HELP
This swashbuckling art exists today as an Olympic sport.... What is the simple subject and what is the simple predicate?
what surface phenomenon s​
What is butterfly in Spanish
Divide p(x)=x^3-4x^2+x+6 by (x-3). Find the remainder and the quotient.
Identify three places where a person can obtain information about art and artists.
Hotdogs come in packages of 10, while rolls come in either 8 or 12. What is the smallest number of packages of each you have to buy in order to have the same nu
The author’s attitude toward stair climbing can be best described as
HELP SOMEONE FOR 20 POINTS
solve using the multiplication principle. Don't forget to perfom a check -3/5x = 6/35