If its a reflection across the y axis the x value is reflected and the y value stays the same, so (-3,7)
Xy = 50
x + y = 15
x = 15 - y
xy = 50
(5 - y)y = 50
5y - y^2 = 50
y^2 - 5y + 50 = 0
(y - 5)(y - 10) = 0
y - 5 = 0 or y - 10 = 0
y = 5 or y = 10
x + y = 15
For y = 5:
x + 5 = 15
x = 10
For y = 10
x + 10 = 15
x = 5
Answer: the numbers are 5 and 10.
They are the same measurements, because:
from 10x + 5, first do vertical angle.
then, alternate interior angle,
then vertical angle again,
and another alternate interior angle.
For each vertical and alternate interior angles, the measurements stay the same.
Set them equal to each other, isolate and solve for x.
10x + 5 = 11x - 1
First, isolate the x. Subtract 10x from both sides, and add 1 to both sides
10x (-10x) + 5 (+1) = 11x (-10x) -1 (+1)
Simplify
5 + 1 = 11x - 10x
6 = x
x = 6
6 is your answer for x.
hope this helps
(a) need to find the number of books, we'll call it "b". then the money (6w) minus the cost of books (17b) equals change left over (w)
6w - 17b = w
6w - w = 17b
5w = 17b
(5/17)w = b
(b) if w = 34
(5/17) *34 = b
10 = b
