Page 235 - Algebra 1

a.
(Ex 1)
b.
(Ex 2)
c.
(Ex 3)
Find the x- and y-intercepts for -6x + 9y = 36. Graph 4x+ 7y = 28 using the x- and
y-intercepts.
Find the x- and y-intercepts on the graph.
Application: Play Tickets
At a school play, student tickets are $5 and adult tickets are $8. Let x be the number of student tickets sold. Let y be the number of adult tickets sold. The equation 5x + 8y = 400 shows that one drama club member raised $400 from ticket sales. Find the intercepts and explain what each means.
SOLUTION
Substitute 0 for y and solve for x. Then substitute 0 for x and solve for y.
Example
5
Math Reasoning
Verify Use the facts of the problem to show that the solution is correct.
5x + 8y = 400 5x + 8(0) =400 5x =400
5x + 8y = 400 5(0) + 8y =400 8y =400
5x =400 8y =400 __ __
55 88 x = 80 y = 50
The x-intercept is 80. The y-intercept is 50.
The x-intercept shows that if the drama club member sold no adult tickets, 80 student tickets were sold. The y-intercept shows that if no student tickets were sold, 50 adult tickets were sold.
Lesson Practice
y
x
O
-6
-4
-2
-2
-4
d.
(Ex 4)
e.
(Ex 5)
Write 4y = 12x - 12 in standard form. Then graph the equation using the x- and y-intercepts.
Athletics Hirva jogs 6 miles per hour and bikes 12 miles per hour. The equation 6x + 12y = 24 shows that she has gone a total of 24 miles. Find the intercepts and explain what each means.
-6
220 Saxon Algebra 1