Question

What are the coordinates (x, y) at which the graphs of 3.6x − 2y = 6 and −2.7x + y = 3 intersect? Round to the nearest tenth if necessary.

Answer 1

3.6x - 2y = 6
-2.7x + y = 3.....multiply by 2
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3.6x - 2y = 6
-5.4x + 2y = 6 (result of multiplying by 2)
----------------add
-1.8x = 12
x = 12/-1.8
x = - 6.67 (or -20/3)

3.6x - 2y = 6
3.6(-6.67) - 2y = 6
-24.01 - 2y = 6
-24.01 - 6 = 2y
-30.01 = 2y
-30.01 / 2 = y
-15 = y

solution : (-6.67, -15)