Question

any math experts? Geometry


1.Justify each step in solving the equation 4x=7(x-3) by writing a reason for each statement.
1. 4x=7(x-3)
2. 4x=7x-21
3. -3x=-21
4. x=7

Answer 1

1. always write down the original equation
2. eliminate the brackets by performing the multiplication (distributive property), so you get separate terms to work with
3. Subtract 7x left and right (or: bring the 7x to the left and flip its sign)
4. Divide left and right by -3.

Answer 2

1. you have to distribute the 7 into (x-3) resulting in 4x=7x-21
2. you put the x's on one side and leave the constant on the other. so subtracting 7x from both sides and leaving you with -3x=-21
3. you must divide both sides by a negative 3 in order to have the variable alone/isolated. leaving you with x=7
4. x=7 because if you put 7 in for x both sides of the equation will be equal to each other.