Solve the following system of linear equations by graphing: -x+y = -7 4x + 4y = 20
1 answer:
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Answer:
x = 5
Step-by-step explanation:
Using Pythagoras' identity in the right triangle.
The square on the hypotenuse is equal to the sum of the squares on the other 2 sides, that is
x² + 12² = 13², so
x² + 144 = 169 ( subtract 144 from both sides )
x² = 25 ( take the square root of both sides )
x = = 5