r = 8
See explanation below
Step-by-step explanation:
a) -3(6 - r) = 6
To get the corect solution, we solve the expression
The first thing we do, is to expand the parenthesis:
-3 × 6 -3 × -r = 6
Multiplication of same sign gives positive number. Multiplication of opposite signs give negative number.
-18 + 3r = 6
collect like terms by adding 18 to both sides:
-18 + 18 + 3r = 6 + 18
3r = 24
divide both sides by 3:
3r/3 = 24/3
r = 8
b) The error was in the multiplication. When -3 was multiplied by -r, it was written as -3r instead of 3r. This affected the workings and the final answer.