A variable needs to be eliminated to solve the system of equations below. Choose the correct first step.
–9x – 10y = -42
–9x + 7y = 60

The triangle will be in the first quadrant after the 1st transformation

The triangle will be in the fourth quadrant after the 2nd transformation

Step-by-step explanation:

* Lets revise translation and reflection

- Horizontal translation means move the figure to right or to left

- Vertical translation means move the figure up or down

- Reflection across x-axis reverses the figure from up the x-axis to

down the x-axis or reverses it from down the x-axis to up the x-axis

* Lets solve the problem

- Triangle △ABC is in the first quadrant

- It translated along ‹ 3, 7 ›

- Then reflected across the x-axis

- We need to know the image of the triangle after first transformation

lies in which quadrant and after the second transformation lies in

which quadrant

∵ The triangle in first quadrant

∵ The translation is <3 , 7>

- That means the triangle is translated 3 units to the right and

 7 units up

∴ The triangle still in the first quadrant

* The triangle will be in the first quadrant after the 1st transformation

∵ The triangle reflected across the x-axis

- That means the triangle is reversed from up the x-axis to down

the x-axis

∴ The triangle is reversed to the fourth quadrant

* The triangle will be in the fourth quadrant after the 2nd transform