variable
powers of numbers
100

solve if r=5

r + 7 - r = ?


r=7

100

Find the value of 2 to the power of 4.

16

200

Solve if g=-2

5 + g - 4 = ?

g=-1

300

Solve if x=1/2

x × 2 + 7 = ?

x=8

400

 Solve for x: 2x + 5 = 11

 

 x = 3

500

 Sarah has n number of books. She buys 4 more. Now she has 15 books. How many books did she have originally? Write the equation and solve.

n=11