Answer:
5r + 2
Step-by-step explanation:
9r-5r+2+r=5r+2
\mathrm{Group\:like\:terms}
=9r-5r+r+2
\mathrm{Add\:similar\:elements:}\:9r-5r+r=5r
=5r+2
Use the difference of 2 squares (a - b)(a + b) = a^2 - b^2:-
(x - 1/x)(x + 1/x) = x^2 - (1/x)^2
= x^2 - 1/x^2
(x ^2 - 1/x^2)(x^2 + 1 /x^2)
= x^4 - 1/x^4
(x^4 - 1/x^4)(x^4 + 1/x^4)
= x^8 - 1 /x^8 Answer
-x<-x+7(x-2)
-x<-x+7x-14 Distribute the 7
-x<6x-14 Combine like terms
-7x<-14 Move all variables to one side
x>2 Divide by -7 to isolate the variable
8 stamps. Multiply 2/3 by 12 and you have your answer
