Can these three side lengths make a triangle? (Hint: use the Triangle
Inequality Theorem)*

No

Step-by-step explanation:

Triangle inequality theorem : Any side of a triangle must be shorter than the other two sides added together.

Let's check if this theorem holds good with these side lengths

3< 9+5 (holds good)

5< 9+3 (holds good)

9< 5+3 (does not hold good)

So, these 3 sides cannot make a triangle

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