<u>The question was rewritten because it has an obvious mistype.</u>
Answer:
<em>The coordinates of B' are (-3,-15)</em>
Step-by-step explanation:
We are given the point A(-3,-1) and we know it was dilated to the point A'(-9,-3) by some scale factor.
The scale factor can be found by dividing each coordinate of A' by the same coordinate of A. Let's call the factor as k:
k = -9/(-3) = 3
k = -3/(-1) = 3
Thus the scale factor is 3.
If we apply the same factor to B(-1,-5), we get the coordinates of B' as:
B'( 3*(-1) , 3*(-5) ) = B'(-3,-15)
The coordinates of B' are (-3,-15)
-3/4x + 5/6 y = 15
Multiply through by 6
-9/2x + 5y = 90
Add 9/2x to both sides
5y = 90 + 9/2x
Divide both sides by 5
y = 18 + 9/10x
y = 9/10x + 18
Comparing with the general equation of a straight line y = mx + c
Gradient (m) = 9/10 or 0.9
and the y - intercept (c) = 18
First, let's put the second equation, <span>x-2.23y+10.34=0, in terms of y:
x - 2.23y +10.34 = 0
2.23y = x + 10.34
y = .45x + 4.64
Now we can substitute the right side of this equation for y in the first equation
</span><span>y=2x^2+8x
.45x + 4.64 = 2x^2 + 8x
Turn it into a quadratic by getting 0 on one side:
2x^2 + 8x - .45x - 4.64 = 0
2x^2 + 7.55x - 4.64 = 0 Divide both sides by 2
x^2 + 3.76x - 2.32 = 0
x =( -b +/- </span>√(b² - 4ac) ) / 2a
x =( -3.76 +/- √(14.14 + 9.28)) ÷ 2
x = .54 or -4.31
Plug the x values into y = .45x + 4.64
y = .45 (.54) + 4.64
y = 4.88 when x= .54
y = .45 (-4.31) + 4.64
y = 2.70 when x= -4.31
Solution set:
{ (0.54, 4.88) , (-4.31, 2.70) }