Question

Two sides of a triangle

Answer 1

step 1: open brackets n rmb to flip the signs

step 2 (optional): rearrange to make the equation clearer to add/minus

length of 3rd side:

(8x + 3) - (2x + 1) -(5x + 2)

= 8x + 3 - 2x -1 - 5x -2

= 8x -2x -5x +3 -1 -2

= x

Therefore, length of 3rd side is X cm.

---

If perimeter = 75cm,

8x +3 = 75

8x = 75-3

8x = 72

x = 9 cm

Therefore,

1st side = 2(9) +1

= 19 cm

2nd side = 5(9) +2

= 47 cm

3rd side = 9 cm