Q:

a. Write five number pairs (r,s) to solve (r-2) (s+1) = 70. You can use negative numbers and fractions. b. Write five number pairs (r,s) to solve (r-2) (s+1) = 0. You can use negative numbers and fractions. c. Make a list of every number that could be used to replace r to solve (r-3) (r+5) = 0.

Accepted Solution

A:
we have that
(r-2) (s+1) = 70

let's assume values ​​of r to find the value of s and assume values of s to find the value of r

Part 1) for r=0
(0-2)*(s+1)=70-------> -2s-2=70-----> 2s=-72-----> s=-36
the first point is (0,-36)

Part 2) for s=0
(r-2)*(0+1)=70-------> r-2=70------> r=72
the second point is (72,0)

Part 3) for r=3
(3-2)*(s+1)=70-----> s+1=70------> s=69
the third point is (3,69)

Part 4) is for s=-2
(r-2) (-2+1) = 70-----> -r+2=70-----> r=-68
the fourth point is (-68,-2)

Part 5) is for r=4
(4-2) (s+1) = 70-----> 2s+2=70---> 2s=68----> s=34
the fifth point is (4,34)

Part 6) Make a list of every number that could be used to replace r to solve
(r-3) (r+5) = 0
for (r+5)=0------> r=-5
for (r-3)=0-------> r=3
therefore
the solution is
r=-5
and 
r=3

alternative method
 graph the equation and look for the points of intersection with the x-axis

using a graph tool
see the attached figure