Point J(-2,1) and point K(4,5) form a line segment JK. For the point P that partition ms JK in the ratio 3:7, what is the y-coordinate of P?


A. 3/7

B. 6/5

C. 11/7

D. 11/5

Respuesta :

We are given coordinates of point J and point K as J(-2,1) and K(4,5).

P divide the JK in ratio m1:m2 =3:7.

We know section formula:

[tex]\left(\frac{m_1x_2+m_2x_1}{m_1+m_2},\:\frac{m_1y_2+m_2y_1}{m_1+m_2}\right)[/tex].

Plugging x1,x2, y1, y2, m1 and m2 in above section formula, we get

[tex]\left(\frac{3\cdot 4+7\cdot \left(-2\right)}{3+7},\:\frac{3\cdot 5+7\cdot 1}{3+7}\right)[/tex]

[tex]=\:\left(\frac{12-14}{10},\:\frac{15+7}{10}\right)[/tex]

[tex]=\left(-\frac{2}{10},\frac{22}{10}\right)[/tex]

[tex]\left(-\frac{1}{5},\frac{11}{5}\right)[/tex].

Therefore, y-coordinate of P is [tex]\frac{11}{5}.[/tex]

Correct option is D. 11/5

Answer:

 

Step-by-step explanation:

We are given the following information in the question:

P divide the line segment JK in the ration 3:7 where J = (-2,1) and K=(4,5)

We use the section formula to calculate coordinates of P.

Formula:

[tex]P(x,y)  = \bigg(\displaystyle\frac{mx_2 + nx_1}{m+n}, \frac{my_2+ny_1}{m+n}\bigg)\\\\\text{where m:n is the ration in which P divides the line segment JK}\\\text{J have coordinates }(x_1,y_1)\\\text{K have coordinates }(x_2,y_2)[/tex]

Putting all the values:

[tex]P(x,y) = \bigg(\displaystyle\frac{3\times 4 + 7\times -2}{3+7}, \frac{3\times 5 + 7\times 1}{3+7}\bigg)\\\\P(x,y) = (-0.2,2.2)[/tex]

Hence, P(-0.2,2.2) divides the line segment JK in the ratio 3:7.