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

@campbell_st

Answer 2

I only need help with part B

Answer 3

ok... so what solution did you get..?

Answer 4

for part A?

Answer 5

@campbell_st

Answer 6

yes can you post the solution to part A

Answer 7

-6x+14y=-32 I got this I multiplied first equation by 2

Answer 8

ok.... this is what I would have done

I would multiply every term in the 1st equation by -3.

this would allow you to eliminate x

equation 2 doesn't change


9x - 21y = 48
-9x +5y = 16 add the 2 equations
---------------
-16y = 64

so y = -4

substitute this into either of the original equations to find x.

does that make sense...?

Answer 9

yes thanks you soo much

Answer 10

ok... so when you get the solution

part B seems to be asking you to substitute the values into

9x - 21y = 48 to show the solution is correct