Question

Find x if distance between points L(x,7)and M (1,15) is 10.

Answer 1

Answer:

x=7,-5

Step-by-step explanation:

distance formula: √((X2-X1)²+(Y2-Y1)²)

substituting the values,

√((1-x)²+(15-7)²) = 10

(1-x)²+ 64 =100

x²-2x+65=100

x²-2x-35 =0

solving the quadratic equation,

x=7,-5

hope that helps ;)

Answer 2

Answer:

LM = $\\ \sf{\sqrt {{( x2 - x1 )}^{2} + {(y2 - y1)}^{2}}}$

$\\ \longrightarrow \sf{10 = \sqrt {{( 1 - x)}^{2} + {(15 - 7)}^{2}}}$

$\\ \longrightarrow \sf{10 = \sqrt {{( 1 - x)}^{2} + {(8)}^{2}}}$

$\\ \longrightarrow \sf{10 = \sqrt {{( 1 - x)}^{2} + 64}}$

$\\ \longrightarrow \sf{100 = {( 1 - x)}^{2} + 64}$

$\\ \longrightarrow \sf{100 - 64 = {( 1 - x)}^{2}}$

$\\ \longrightarrow \sf{36 = {( 1 - x)}^{2}}$

Taking square root on both sides

$\\ \longrightarrow \sf{\sqrt {36} = \sqrt {{( 1 - x)}^{2}}}$

$\\ \longrightarrow \sf{ +\:or\:- 6 = 1 - x }$

$\\ \longrightarrow \sf{ 1 - x = 6\: or 1 - x = -6 }$

$\\ \longrightarrow \sf{ - x = 6 - 1 \: or \:- x = -6 - 1}$

$\\ \longrightarrow \sf{ - x = 5 \: or \:- x = -7}$

$\\ \longrightarrow \sf{ x = -5 \: or \: x = 7}$

hope it helps you