How do I know if it’s similar, congruent or neither?

These two triangles are congruent.

Step-by-step explanation:

You know this bc the markings on the drawing show that Angle B and Angle D are congruent. Also that AB is parallel to CD. This means that Angle BAC and Angle DCA are congruent by ALTERNATE INTERIOR ANGLES. Also, AC is congruent to itself. That makes the two triangles congruent by ANGLE-SIDE-ANGLE.

Now, you need to know that "congruent" triangles (and shapes in general) are the same size and shape. "Similar" triangles (shapes) are the same shape but not necessarily the same size.

5x+40

5(x + 8)

7x - 49

7(x - 7)

18x + 9

9(2x + 1)

15x - 10

5(3x - 2)

step-by-step explanation:

for number one all you have to do is factor 5 out of 5x + 40

for number 2 factor 7 out of 7x - 49

for number three factor 9 out of 18x + 9

for number four factor 5 out of 15x - 10

5x+10 is the correct one

hope this