1-step Equations: + and – 2/27/13In elementary school, you solvedequations that looked like this:In Algebra, we just use a variableinstead of the box!We could rewrite the same equationlike this: x + 3 = 5
To solve:Need to get x by itself.We must “undo” whatever has been doneto the variable.Do the same to BOTH SIDES of the = sign!Answer should be: x = some number.
Equations Have to Balance!Both sides of the = sign must “weigh” thesame!When you change one side, do the sameto the other side, so it stays balanced!x + 3 = 7
Examples:Solve each equation. Check your answers!x + 3 = -7 m – 6 = 8
You Try!Solve each equation. Check your answers!x – 9 = -6 16 + n = 10
1-step Equations: × and ÷ 3/11/13Just like with adding and subtracting,we need to “undo” what is done to x.Use division to “undo” multiplication.Use multiplication to “undo” division.Remember: A fraction bar meansdivide!Example: says x divided by 3!
Basic 2-Step Equations 3/13/13A lot like 1-step equations!Goal: Get x by itself!Need to “undo” what is done to x.Always do the same thing to BOTH SIDES!Use Order of Operations backwards:Add/Subtract firstMultiply/Divide last
2 Variables- Same Side 3/21/13Some equations have variables in morethan one place.When variables are on the same side ofthe = sign:First, Combine Like Terms Like terms may NOT cross the = sign!Then, solve like a 2-step