Question

help with systems of equations !

solve
x + 2y = 13

4x + 8y = -9

Answer 1

@jim_thompson5910

Answer 2

There are to ways to solve. Substitution or elimination. Which way do u want to use?

Answer 3

elimination!!

Answer 4

wait a sec is it 3,5 ?

Answer 5

No, that's not correct.

So for elimination, the first thing I want to do is multiply 4 on both sides in the first equation

Answer 6

ok

Answer 7

4x + 8y = 52

Answer 8

and when you add you get 8x + 16y = 43

Answer 9

Then u want to subtract the 2 equations

Answer 10

isn't it add

Answer 11

No, u subtract. If u want to add, u can multiply one of the equaions by -1. Whether u add or subtract, ur goal is to try to elimate one of the variables

Answer 12

ok.. so i got 61

Answer 13

actually 0x + 0y = 61

Answer 14

Correct. Which is also 0=61. And since this isn't true, then this system of equaions has no solutions which means that they are parallel lines

Answer 15

so the answer is no solutions.

Answer 16

Correct. Because 0 doesn't not equal 61

Answer 17

ok thanks

Answer 18

No problem

Answer 19

i have a couple more i don't need you to do the whole thing because i know its long but i just need to know what to multiply the first equation by ,

Answer 20

like this one

3x - 5y = 17

9x - 15y = -4

Answer 21

do i multiply 9 to both sides of the first one ?

Answer 22

Ok. So u can look at the x's. one has a 3 and the other has a 9. In order to get rid of them, u would have to make them =. Since 3x3=9, u can just multiply the first equation both sides by 3

Answer 23

ahh so the goal is to get opposite coefficients

Answer 24

then we add or subtract ?

Answer 25

Becuz after multiplying, u have 9x and 9x and in order to make it=0 u would have to subtract. So in this case, u would subtract

Answer 26

ok thanks

Answer 27

ok i think im stuck i got -30y = 13

Answer 28

I think u did something wrong

9x-15y=51
- (9x-15y=-4)
------------------
0x+0y=55
So
0=55

Answer 29

wow.

Answer 30

you're so smart lol

Answer 31

so its no solution again ?

Answer 32

Haha. Thanks. And yes, no solution is correct

Answer 33

are these hard for you

Answer 34

Not really especially compared to what I'm doing now

Answer 35

calculus

Answer 36

No, geometry h

Answer 37

oh ok