Question

3. Solve the system by the substitution method. Show your work.
2y - x = 5
x2 + y2 - 25=0 ?

Answer 1

y(4y + y - 20) = 0 so, y = 0
or 4y+y-20 = 0 5y -20 = 0 y =45y-20=05(4)-20=00=0 x = 2y -5when y=4x = 8-5 =32y - x = 5x2 + y2- 25 = 02y - x = 5 2y - 5 = x so x = 2y - 5 (2y - 5)² + y² - 25 = 0
(2y - 5)(2y - 5)
4y² - 10y - 10y + 25
4y² - 20y + 25
4y² - 20y + 25 + y² - 25 = 0
4y² + y² - 20y = 0
4y² + y² - 20y = 0
y(4y + y - 20) = 0
y=0
x= -5
2y - x = 5
2(0) - x = 5, so x= -5)
(-5,0) this wwas my answer

Answer 2

my teacher said 3. Solve for x using equation 1 and then substitute this in the second equation. Once you simplify you will have a quadratic equation which you can factor and solve. Remember to factor out the GCF first.. The solutions should be written as ordered pairs (x1,y1) and (x2,y2).

Answer 3

@Abhisar @Clalgee @dan815 @ganeshie8

Answer 4

if my answer is correct what did she mean she only gave me two out of five points for thisw question

Answer 5

@ShadowLegendX

Answer 6

@nevermind_justschool

Answer 7

@peachpi

Answer 8

For one, you should have two solutions

Answer 9

or did I miss it?

Answer 10

somone sadi to use (3,4)

Answer 11

\(2y - x = 5\) → \(x=2y-5\)
\(x^2 + y^2 - 25=0\)

\((2y-5)^2+y^2-25=0\)
\(4y^2-20y+25+y^2-25=0\)
\(5y^2-20y=0\)
\(5y(y-4)=0\)
\(y=0,~y=4\)

Back substitute to find x

Answer 12

ok I see. On this line you needed to solve for both y's

y(4y + y - 20) = 0
You got \(y = 0\), but missed \(4y+y-20=0\)

Answer 13

wait there were two y's

Answer 14

yep. That's a quadratic equation so it has two solutions

Answer 15

ohh so i nned solve for the second one right

Answer 16

yes

Answer 17

can you help me withthat im so sleepy but i needa get this done

Answer 18

I already put it up there. It's 4

Answer 19

ohh ik that thnx hahaha see my sleepiness is messing with my brain thnx again padre

Answer 20

np

Answer 21

how do i copy and paste that i cant seem to get it highlighted to copy it and its killing me lol

Answer 22

help me one more time please @peachpi

Answer 23

idk that happens a lot with chrome. try double clicking the whole thing then deleting what you don't want

Answer 24

its mot working when i double click it it hightlights like 1 number

Answer 25

maybe try another browser

Answer 26

i got it highlighted but it wont let me coppy it

Answer 27

is there another way you could write it for me or nah

Answer 28

why can't you use what you had originally. It's right. Just add the line y = 4, x = 3 at the end

Answer 29

ohh ok i thought i needed the whole thing sorry

Answer 30

no, your stuff is good. you just missed one of the solutions, last step.

Answer 31

ok thnx bro gn