1. Objectives
Solve a formula for a given variable.
Solve for y=mx+b

2. Solving for a Variable
Step 1 Locate the variable you are asked to solve for in the equation.
Step 2 Use inverse operations to undo operations and isolate the variable.
Remember: Numbers attached to the variable you want have to be the LAST piece you move!!

3. The formula C = d gives the circumference of a circle C in terms of diameter d.
Solve the formula for the variable d

4. 2. The formula d = rt gives the distance d of an object in terms of rate r and time t.
Solve the formula d = rt for t.
d = rt

5. 3. The formula for the area of a triangle is A = bh,
where b is the length of the base, and h is the height.
Solve for h.
A = bh

6. 4. The formula for an object’s final velocity is f = i – gt, where i is the object’s initial velocity, g is acceleration due to gravity, and t is time.
Solve for i.
f = i – gt
f = i – gt
+ gt gt
f + gt = i

7. Solving for y = mx+b Steps: Locate the variable “y”
Using inverse operations move the terms with “x” attached to them to the opposite side of the = sign.
Using inverse operations get “y” by itself (x or ÷ by what is attached to “y”).

8. DIVIDE BY WHAT IS NEXT TO Y!!!
Solving for y = mx+b
MOVE THE X’S (+ or -)
*To opposite side of = If needed
DIVIDE BY WHAT IS NEXT TO Y!!!
*In 3 places

9. Solving for y = mx+b
1. x + 2y = x – 8y = – 56

10. Solving for y = mx+b
3. 4x – 8y = x – y = 3

11. Solving for y = mx+b
5. 3y =2x x + 10y = – 20

12. Solving for y = mx+b
7. 2x + y = 4
8. x – y = 4