00:01
We need to solve the following using the addition method.
00:03
So we're going to multiply the top equation by 5.
00:06
The bottom equation by negative 2, so we can cancel out our r's.
00:12
So we get 20k minus 10r is equal to negative 20.
00:17
We get negative 6k plus 10r is equal to negative 36.
00:23
So ours cancel out.
00:25
We're left with 14k is equal to negative 56.
00:30
56 divided by 14 is k is equal to negative 4.
00:35
So we're going to take that and plug it back in and solve for r.
00:38
So we have 4 times negative 4 minus 2r is equal to negative 4.
00:44
We have negative 16 minus 2r is equal to negative 4.
00:47
We add 16 to both sides...