Forming Equations

I think of a number, add 8 and my answer is 13.

Which equation is correct?

• x+8= 13

• 8+13=x

• x+13=8

Tags

CCSS.HSA.CED.A.3

I think of a number, add 8 and my answer is 13. What number was I thinking off?

• 8

• 13

• 5

• 21

Tags

CCSS.1.OA.D.8

I think of a number, double it, then subtract 5 and my answer is 19

• x2 - 5 = 19

• 2x - 5 = 19

• 2x + 5 = 19

I think of a number, double it, then subtract 5 and my answer is 19.

What number did I start with?

• 12

• 48

• 7

Tags

CCSS.7.EE.B.4A

I think of a number, subtract 3, then half it, my answer is 11.

Which is the correct equation?

• $x-3\div2=11$

• $x-\frac{3}{2}=11$

• 
  

  $\frac{\left(x-3\right)}{3}=11$
  

I think of a number, subtract 3, then halve that and my answer is 11. What number did I start with?

• 8

• 25

• 16

Tags

CCSS.7.EE.B.4A

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