Point P is the centroid of LMN. Find PN

PN = 14

QP = 7

Step-by-step explanation:

Extend PQ to R so that QR=PQ

MQ = QL  (known, mid-point)

MPLR is parallelogram (diagonal bisect each other)

MP // RL          NP/PR = NE/EL = 1/1 (E mid-point, known)

NP = PR

PQ = QR = 1/2 PR = 1/2 NP

NP = 2 PQ

NP + PQ = 2PQ + PQ = 3 PQ = QN = 21

PQ = 7

PN = 14

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15