2.3 + r = 7.1

solve for r

r = 4.8

Step-by-step explanation:

2.3 + r = 7.1

r + 2.3 = 7.1

r = 7.1 - 2.3

r = 4.8

2.3+r=7.1

move all terms to the left:

2.3+r - (7.1) = 0

add all the numbers together, and all the variables

r-4.8=0

move all terms containing r to the left, all other terms to the right

r=4.8 is the answer