Respuesta :

Riia

Here we use midsegment rule which states that if a segment joining two midpoints of the two sides ,then it is parallel to third side and equal to half of it .

That is,

SP = 0.5 LN

3x+1=0.5(10x-6)

6x+2 = 10x-6

Subtracting 6x to both sides and adding 6 to both sides

8 = 4x

Dividing both sides by 4

x=2

Substituting x in SP, that is SP =3(2)+1 =7

2*SP = LN

2(3x+1)=(10x-6)

6x+2=10x-6

10x-6x = 2+6

8x=8

x=1

SP=3x+1 =3(1) +1 =4

SP=4

Answer is D. SP=4