Question

Use substitution to solve the system.
x = 3y - 17
−5x + 2y = 33

Answer 1

you see something here? you have an expression for x already x = 3y-17

what do you think you can do with that?

Answer 2

put both in standard form first

Answer 3

plug the value of x u got in 1st equation
in the 2nd equation

Answer 4

looks like @Photon336 got the question first ;'c

Answer 5

woah so many people haha :o

Answer 6

divide right?

Answer 7

no no..... u jst need to plug the value in 2nd equation

Answer 8

how :s

Answer 9

like in the first equation u got x = 3y - 17
now just plug tht in 2nd equation

Answer 10

@Ashleyy_Smith
http://www.purplemath.com/modules/systlin4.htm

Answer 11

so on substituting the value of x in 2nd equation.... it would be
\[-5(3y -17) + 2y = 33\]

Answer 12

Do I distribute now?

Answer 13

now u got the equation with only one variable.....
deal with it... :P
get y .... plug its value in any of the equation and get x

Answer 14

so what @rishavraj is showing you is the substitution way
there is also a elimination way

Answer 15

yes but I have to give the answer in substitution form :s

Answer 16

its a method

Answer 17

answer is gonna remain the same -_- @Ashleyy_Smith bt if u supposd to show ur work ...then u neeed to solve it by substitution method

Answer 18

so -15+85+2=33 right?

Answer 19

wheres y in the equation ??? -_-

Answer 20

-5(3y - 17)y + 2y = 33
-15y + 85 + 2y = 33
solve for y

Answer 21

oops after the 15 and the 2

Answer 22

okkk go on solve it ...

Answer 23

I add the y's first right?

Answer 24

go on....... just get me the y

Answer 25

-13y

Answer 26

so its -13y + 85 = 33
u mean tht??

Answer 27

yes

Answer 28

go on...... then get y

Answer 29

I got a long decimal when I divided 72 by 33

Answer 30

why decimal.....
how do u solve y + 2 = 5 ????

Answer 31

ok tell me whts the value of y , when y + 2 = 5 ??

Answer 32

would it be 5?

Answer 33

for y + 2 = 5 ????y = 5>??

Answer 34

ohhhhh oops my bad 3

Answer 35

see u need to isolate the variable on one side of the sign of equality.....
so like y + 2 = 5 ,...... u need to subtract 2 on both sides...
so u will be having y + 2 - 2 = 5 -2
y = 3
u get tht ?? @Ashleyy_Smith

Answer 36

ooo good..... now try
-13y + 85 = 33

Answer 37

wht do u think would be the first step ??

Answer 38

oops

Answer 39

hmmmm ??

Answer 40

solve
-13y + 85 = 33

Answer 41

uuummm. would I subtract 33 from 85?

Answer 42

as I told u need to isolate the variable .... so u need to subtract __ on both sides

Answer 43

so 72 and 20?

Answer 44

wht is tht now??? -_- u simply need to subtract 85 on both sides

Answer 45

oh

Answer 46

so it would be
-13y = -52
now wht??

Answer 47

divide and get -4

Answer 48

means -y = -4

Answer 49

so whts the value of y??

Answer 50

u just said y = -4 :o

Answer 51

its
-y = -4

Answer 52

so u mean of x?

Answer 53

oh

Answer 54

theres a negative sign
-y = -4
so y = ??

Answer 55

4

Answer 56

good ...now plug the value in any equation....lol prefer the 1st one in this case

Answer 57

x=3y-17
x= 3(4) - 17
x = 12y - 17

Answer 58

right?

Answer 59

x = 12 -17 -_-
so x = ??

Answer 60

5

Answer 61

-5

Answer 62

oooo coolll... so its x = -5 and y = 4

Answer 63

good work :))

Answer 64

@Ashleyy_Smith u got this Substitution method??

Answer 65

yes :) ill practice more on it tomorrow

Answer 66

good :)))
All the Best

Answer 67

thank u!