Download Lesson 2

Lesson 2-5
Solving Equations by Adding or
Subtracting
• Solving an equation is like keeping a barbell
balanced.
• If you add weight to or subtract weight from
one side of the bar, you must do the same on
the other side
• When you solve an equation the goal is to get
the variable alone on one side of the equation
• The value on the other side tells you the
solution to the original equation.
• You use inverse operations, which undo each
other, to get the variable alone
• The inverse of addition is
• The inverse of subtraction is
• The inverse of multiplication is
• The inverse of division is
• Subtraction Property of Equality
– You can subtract the same number from each side
of an equation
10 = 2(5)
• Solve
x+6=4
Always check your answer by putting it into the
original equation
• x+8=3
• 5=d+1
• c + (-4) = -5
• Addition Property
– You can add the same number to each side of an
equation
8 = 2(4)
• Solve
b – 12 = – 49
25 = p – 14