MATH

2-step equations

100

4(10+15)

100

200

12(7+5k)

84+60k

300

4(3b+m)

12b+m

400

9(5y+12)

108

500

Lena bought 3 notebooks and a pen.
Each notebook costs $4. The total cost was $19.
How much did the pen cost?

x=7

Grab Bag

100

3x+5=20

x=5