7x+8y=9
-4x-6y=-8
solve for x and y
To solve for x and y, we can use either substitution or elimination method. Here we will demonstrate the elimination method:
Multiply the first equation by -2:
-14x - 16y = -18
Add this equation to the second equation:
-14x - 16y = -18
-4x - 6y = -8
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-18x - 22y = -26
Now we can solve for x by isolating it:
-18x - 22y = -26
-18x = -26 + 22y
x = (26/18) - (22/18)y
x = (13/9) - (11/9)y
We can substitute this expression for x into either of the original equations to solve for y. Let's use the first equation:
7x + 8y = 9
7[(13/9) - (11/9)y] + 8y = 9
(91/9) - (77/9)y + 8y = 9
(17/9)y = (8/9)
y = 8/17
Substitute this value of y back into the expression we found for x:
x = (13/9) - (11/9)y
x = (13/9) - (11/9)(8/17)
x = (13/9) - (88/153)
x = (305/153)
Therefore, the solution is (x,y) = (305/153, 8/17).
it doesnt show on choices here are options
A: x=-9, y=9
B: x=-1 y=2
C: x=-4 y=4