3. greg is going to solve the system of linear equations below. first equation: 74x10 second equation: 74x10 which of the following would greg not use to solve this system of equations?
a. solve the second equation for y and then substitute the result into the first equation.
b. multiply the first and second equation by -6 to eliminate the y variable.
c. solve the first equation for y and then substitute the result into the second equation.
d. multiply the first equation by 3 and the second equation by 2 to eliminate the y variable.

4. when using elimination to solve 2x-3y = 4 7x+ 6y = -1 what would be a possible first step?
a. 4x – 6y = 8 7x + 6y = -l
b. x = 3/2y + 2 7x + 6y = -1
c. 2x -3y = 4 x = -6/7y – 1/7
d. y = 2/3x – 4/3 7x + 6y = -1

5 sam purchased two bottles of water and three hot dogs at the ballpark for $8.50. mary purchased one bottle of water and two hot dogs for $5.25. what system of equations could be solved to determine the prices in dollars of a hot dog (7x8 ) and a bottle of water (9x5 )?
a. 105x30
b105x30
c 93x30
d. 105x30

6. given: 2x + y = 0 x – y = 6 what is the solution to the system of equations? a. (1, -2)
b. (2, -4)
c. (4, -2)
d.(5, -1)

7 solve: 3x + y = -8 2x – y = 3
a (-1, -5)
b (3,3)
c (-2, -2)
d infinitely many solutions

d. it is a convex pentagon because it has five sides and none of the sides would extend into the inside of the polygon.

step-by-step explanation:

when functions are first introduced, you will probably have some simplistic "functions" and relations to deal with, usually being just sets of points. these won't be terribly useful or interesting functions and relations, but your text wants you to get the idea of what the domain and range of a function are. small sets of points are generally the simplest sorts of relations, so your book starts with those.

step-by-step explanation:

state the domain and range of the following relation. is the relation a function?

{(2, –3), (4, 6), (3, –1), (6, 6), (2, 3)}

the above list of points, being a relationship between certain x's and certain y's, is a relation. the domain is all the x-values, and the range is all the y-values. to give the domain and the range, i just list the values without duplication:

domain: {2, 3, 4, 6}

range: {–3, –1, 3, 6}

(it is customary to list these values in numerical order, but it is not required. sets are called "unordered lists", so you can list the numbers in any order you feel like. just don't duplicate: technically, repetitions are okay in sets, but most instructors would count off for this.)

while the given set does indeed represent a relation (because x's and y's are being related to each other), the set they gave me contains two points with the same x-value: (2, –3) and (2, 3). since x = 2 gives me two possible destinations (that is, two possible y-values), then this relation is not a function.

note that all i had to do to check whether the relation was a function was to look for duplicate x-values. if you find any duplicate x-values, then the different y-values mean that you do not have a function. remember: for a relation to be a function, each x-value has to go to one, and only one, y-value.

state the domain and range of the following relation. is the relation a function?

{(–3, 5), (–2, 5), (–1, 5), (0, 5), (1, 5), (2, 5)}

i'll just list the x-values for the domain and the y-values for the range: