Respuesta :
Given:
The equation of a line is:
[tex]2y+3x=10[/tex]
The line is dilated by factor 3.
To find:
The result of dilation.
Solution:
The equation of a line is:
[tex]2y+3x=10[/tex]
For [tex]x=0[/tex],
[tex]2y+3(0)=10[/tex]
[tex]2y+0=10[/tex]
[tex]y=\dfrac{10}{2}[/tex]
[tex]y=5[/tex]
For [tex]x=2[/tex],
[tex]2y+3(2)=10[/tex]
[tex]2y+6=10[/tex]
[tex]2y=10-6[/tex]
[tex]2y=4[/tex]
Divide both sides by 2.
[tex]y=\dfrac{4}{2}[/tex]
[tex]y=2[/tex]
The given line passes through the two points A(0,5) and B(2,2).
If the line dilated by factor 3 with origin as center of dilation, then
[tex](x,y)\to (3x,3y)[/tex]
Using this rule, we get
[tex]A(0,5)\to A'(3(0),3(5))[/tex]
[tex]A(0,5)\to A'(0,15)[/tex]
Similarly,
[tex]B(2,2)\to B'(3(2),3(2))[/tex]
[tex]B(2,2)\to B'(6,6)[/tex]
The dilated line passes through the points A'(0,15) and B'(6,6). So, the equation of dilated line is:
[tex]y-y_1=\dfrac{y_2-y_1}{x_2-x_1}(x-x_1)[/tex]
[tex]y-15=\dfrac{6-15}{6-0}(x-0)[/tex]
[tex]y-15=\dfrac{-9}{6}(x)[/tex]
[tex]y-15=\dfrac{-3}{2}x[/tex]
Multiply both sides by 2.
[tex]2(y-15)=-3x[/tex]
[tex]2y-30=-3x[/tex]
[tex]2y+3x=30[/tex]
Therefore, the equation of the line after the dilation is [tex]2y+3x=30[/tex].
