Posted by **Kelly** on Sunday, May 19, 2013 at 12:10am.

I need help with two math problems.

1. A triangle has vertices (1, 4), (1, 1), and (-3, 1). The triangle is dilated by a scale factor of 2, then translated 5 units up, and then rotated 90 degrees counterclockwise about the origin. What are the vertices of the image of the triangle?

2. Use matrices to solve the system.

2x+3y=4

5x+8y=11

I appreciate the help!

- Algebra -
**MathMate**, Sunday, May 19, 2013 at 8:05am
1.

The transformations are:

e(O,2) : dilation about origin of 2 units

t(0,5) : translation 5 units up

r(y,-x) : rotation counter-clockwise 90°

So

(x,y)-> (2x,2y) -> (2x, 2y+5) -> (2y+5, -2x)

So combining it all:

(x,y) -> (2y+5, -2x)

2.

Using Cramer's rule:

Δ=8*2-3*5=1

x=(4*8-11*3)/Δ=-1

y=(2*11-5*4)/Δ=2

Check:

2(-1)+3*2=4

5(-1)+8*2=11

ok.

- Algebra -
**Melania**, Sunday, May 19, 2013 at 11:17am
I'm still confused on the first one. Thank you. I appreciate it.

## Answer this Question

## Related Questions

- Algebra - I'm stuck!! Can someone please help me with this problem?? A triangle ...
- Matrices - A triangle has vertices (1, 4), (1, 1), and (−3, 1). The ...
- geometry - I realy need help please!!!! 1-Describe the translation in words: (x...
- math - A triangle has vertices with coordinates (2, 0), (3, -1), and (-2, -5). ...
- math - A triangle has vertices with coordinates (2, 0), (3, -1), and (-2, -5). ...
- MATH - A triangle with the vertices A(–3, 4), B(3, 1), and C(–1, –5) is dilated ...
- Math - A triangle has vertices at S(1, 1), T(2, -3) and U(4, 0). The triangle is...
- Pre-Calculus - Hi! I need help with this math homework question: If you had a ...
- math - Triangle XYZ has vertices X(-5,3), and Z(7,-6). Find the coordinates of ...
- math - One triangle has vertices A, B, and C. Another has vertices T, R, and I. ...

More Related Questions