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

Gabrielle's age is three times Mikhail's age. The sum of their ages is 56, what is their age?
15/18 + 1/2 - 1/3 - 2/6=
A small publishing company is planning to publish a new book. The production costs will include the time fixed, costs (such as editing) and variable costs (such
two similar cones have surface areas in the ration 4:9. find the ration of their lengths and their volumes
a washer and a dryer cost 659$ combined. The washer costs 91$ less than the dryer, how much was the dryer?
Nearly 50% of water sources in the United States are believed to be polluted. true or false? Explain please?
The "elastic clause" in the U.S. Constitution. What is it?
how are moses, jesus and muhammad basic belief similar to other monotheistic faiths ?
a washer and a dryer cost 659$ combined. The washer costs 91$ less than the dryer, how much was the dryer?
Water that flows downhill along Earth's surface is called