$\triangle ABC\ \text{and}\ \triangle ACD\ \text{are similar. Therefore the sides of triangles}\\\text{ are in proportion:}\\\\\dfrac{y}{9+3}=\dfrac{9}{y}\qquad\text{cross multiply}\\\\y^2=(9)(12)\\\\y^2=108\to y=\sqrt{108}\\\\y=\sqrt{36\cdot3}\\\\y=\sqrt{36}\cdot\sqrt3\\\\\boxed{y=6\sqrt3}$

4 0

3 years ago

Y=3×+7 y=×-9 what is the solution of the equation

Aneli [31]

Since both equations are equal to y you can just make them equal to each other, like this 3x + 7 = x - 9. From there isolate the varible x on one side so that the solution will be on the other side of the equation. I'll do the steps too for you.

3x + 7 = x - 9

2x + 7 = -9

2x = -16

x = -8

Hope this helps :)

7 0

4 years ago

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