Algebra 1 Homework help ! ?

Question

Solve the system by graphing

y = 3x -1

y = -x + 3

NEXT QUESTION

Write a system of equations to model this situation. Then use your system to solve. An elementary school is selling bulbs for a spring fundraiser. A package of tulip bulbs is 1/3 the price of a package of iris bulbs. Your aunt molly buys 5 packages of tulip bulbs and 2 packages of iris bulbs for $33. Find the price of each package of bulbs.

NEXT QUESTION

the graph y = 3/x is translated 4 units down. What is the equation of the new graph ?

I would like to know how to solve these problems. I really need help not just the answers

xo rose

god bless you

Answer 1

First question:

you have a point on each line and the slope.  get graph paper and make a graph. x is horizontal axis, y is the vertical axis.  now put your pencil on x=0, y = -1 (0, -1) and count 3 up, one to the right.  make a dot. then go back to (0, -1) and go three down and one to the left. put a ruler or straight edge on the paper to line up the dots and draw a line that goes across the whole graph and through all of the dots.

go to (0, 3) and repeat the process, this time counting one up and one to the left, then go back to (0, 3) and go one down and one to the right.  connect the dots as before.  the point where the two intersect is the solution.  in (x, y) form, the x coordinate of the point where they intersect is also the value of x in the equations; the y coordinate is the value of y in the equations.

Second Problem:

try calling iris bulbs x and tulip bulbs y.  

the first equation would be the price of the bulbs: tulips = 1/3 iris

the second equation would be Aunt Molly's order: 5 tulips + 2 iris = 33.

So if y is tulips and x is irises,

y = 1/3 x (price of bulbs)

5y + 2x = 33

This first equation gives you the value of y in terms of x.  so in the other equation, you substitute that value for y:

5(1/3 x) + 2x = 33

Solve for x the way you would a one-variable equation.

5/3 x + 2x = 33

5/3x + 6/3 x = 33

11/3 x = 33

multiply both sides by 3/11 (the reciprocal of 11/3) so that you get x by itself

x = 33 (3/11)

x= [33(3)] / [1 (11)]

x= 99/11

x=9

now plug the 9 back into your first equation, y=1/3 x.  so y = 1/3 of 9.

x = 9, y = 3.  so now go to your second equation and put in 9 for x and 3 for y

5(3) + 2(9) = 33

15 + 18= 33

this checks your work.  since both sides add up to 33, you can give the values of x and y as the prices in dollars of irises and tulip bulbs, respectively.

Third problem

the y-intercept of the first line is zero (0,0).  four units down means the new y-intercept is - 4 (0, -4).  the slope remains the same.

so first find the slope of y=3/x by turning 3/x into something TIMES x.

so you have y = ___x as the equation of the line.  then you just write the equation so that b is equal to -4 instead of zero:

y = ___x - 4

hope this helps,

--Reggie