Question

Solve the system by graphing. Y=2x-9 y=-2x-1

Answer 1

(2,-5)

Explanation:

See attachment

One can also solve this by calculation:

y=2x-9

y=-2x-1

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Rearrange either equation to find x. I'll use the first:

y=2x-9

2x = y+9

x = (y+9)/2

Now use this value of x in the second equation:

y = -2x-1

y =-2((y+9)/2)-1

y = (-2y-18)/2)-1

y = -y -9 - 1

2y = -10

y = -5

Now use -5 for y in the rearranged equation:

y = -2x-1

-5 = -2x-1

-2x = -4

x = 2

Solution is (2,-5)

But the question wants a graph solution, which is also fun when you use DESMOS.