How do you solve the system y=4x; 2y-x=16y=4x;2y−x=16?

1 Answer
smendyka
Jan 9, 2017

See full solution process below

Explanation:

Step 1) Because the first equation is already solved for yy we can substitute 4x4x for yy in the second equation and solve for xx:

(2 xx 4x) - x = 16(2×4x)−x=16

8x - x = 168x−x=16

8x - 1x = 168x−1x=16

(8 - 1)x = 16(8−1)x=16

7x = 167x=16

(7x)/color(red)(7) = 16/color(red)(7)7x7=167

(color(red)(cancel(color(black)(7)))x)/cancel(color(red)(7)) = 16/7

x = 16/7

Step 2) We can now substitute 16/7 for x in the first equation and calculate y:

y = 4 xx 16/7

y = 64/7

The solution is:

x = 16/7 and y = 64/7

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