Question

A system of equations is shown below:

-3x + 7y = -16
-9x + 5y = 16

Part A: Create an equivalent system of equations by replacing one equation with the sum of that equation and a multiple of the other. Show the steps to do this. (6 points)

Part B: Show that the equivalent system has the same solution as the original system of equations.

Answer 1

please help

Answer 2

opps should read... multiply every term in the 1st equation by -3.... what is the result

Answer 3

honestly i have no idea ... idk what your talking about can you explain it to me

Answer 4

so its

\[-3 \times -3x + -3 \times 7y = -3 \times -16\]

can you simplify that

Answer 5

no.. ): im sorry im stupid and dont understand math one bit

Answer 6

oops should be

9x - 21y = 48 does that make sense?

Answer 7

i guess is that A?

Answer 8

yes, that's the equivalent equation.... you did that by multiplying every term by -3...

the reason I chose -3... is that you get

9x -21y = 48 when you add the 2 equations x will be eliminated
+ -9x + 5y = 16 which will allow you to solve for y
----------------
-16y = 64

now solve for y.

to get an x value, substitute your answer from y into either equation to get x.

hope that helps

Answer 9

okay i kinda understand.. is that still part a ? or is that to help with b?

Answer 10

so the equivalent equation is 9x -21y = 48

then you need to solve the 2 equations, so you can get the values of x and y

so that is partly done

1. find y if -16y = 64

2. substitute that value into either of the original equations... to get x

Part B

use your solutions and substitute them into the equivalent equation.

to show the solution is correct for the equivalent equation...

hope that makes sense.

Answer 11

im sorry i dont get it )))):