(a) Reflect the point (7, -9) across the y-axis: (b) Reflect the point (7, -9) across the x-axis:

(-7,-9) and (7,9)

Step-by-step explanation:7,-9 so we do across the x so you need a graph for this now x goes left so we plot the coordinates in the third box 7,-9 is in the 4 box so after we plotted that you can see it reflects.Now y coordinate since the y line goes up we plot the coordinates on top of the 4 box where our original coordinates stay now it should be 7,9 the y becomes positive which is 9.

This is not a web answer i answered myself took me some time!

No , theres not enough information provided to Prove that both the triangles are congruent. Here in the figure we can see that there are two triangles ∆ BDA and ∆ BDC. And its given that

The congruence conditions for two ∆s are :-

1) SAS ( Side Angle Side )

→ Two triangles are said to be congruent by SAS if two respective sides of the two triangles and the included angle between two sides are equal.

2) AAS ( Angle Angle Side )

→ Two triangles are said to be congruent by AAS if two angles and one side of triangle is congruent to other two angles and one side of the triangle .

3) SSS ( Side Side Side )

→ Two triangles are said to be congruent by SAS if all the three sides of one triangle is equal to three sides of the other triangle.

4) RHS ( Right Hypotenuse Side )

→ In two right-angled triangles, if the length of the hypotenuse and one side of one triangle, is equal to the length of the hypotenuse and corresponding side of the other triangle, then the two triangles are congruent.

And the given data doesn't satisfies any of the conditions.