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3 votes
Please solve by substitution the following and please show steps:

11x-7y = 14
x-2y=-4

thank you

2 Answers

5 votes
x-2y=-4
x=2y-4

11 (2y-4)-7y=14
22y -44-7y=14
15y-44=14
15y=58
y=58/15
x-2 (58/15)=-4
x-116/15=-4
x=116/15 -4 or 4 can be 70/15
x=46/15
User Vahid Pazirandeh
by
8.3k points
3 votes
11x-7y=14
x-2y=-4
first you'll probably want to have the additive inverse which would make
11x-7y=14 into 22x-14=28
by multiplying the problem by 2 so y cancels out and then you would make
x-2y=-4 into -7x+14y=-28
by multiplying everything by -7
then you would just add those 2 equations to each other which you then get
15x=0 which means x=0 and then you can plug that back into one of the beginning equations to get why like 11(0)-7y=14 which then makes
y=-2 so (0,-2) then you can plug those back into your first equations to check
11(0)-7(-2)=14 which checks out
User Quinton Pike
by
8.5k points

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