Question

8 9 21 5 Puzzle Box Question

Answer 1

Step-by-step explanation:

-7+[-1]=8

-3×[-3]=9

-7×[-3]=21

-1+[-3]=5

Answer 2

Filling the boxes:

2.1       +   5.9    = 8

x              -

10     x   0.9      =  9

=              =

21            5

Given:

□  +   □    = 8

x         -

□   x    □   = 9

=         =

21       5

To Find:

• Fill the boxes with numbers so that all equations are satisfied

Solution:

Step 1:

Assume variable a  in first box in top row then   8 - a will be 2nd in top row

and 21/a  in first in bottom row   and assume b is 2nd box in bottom row

a       +   (8-a)    = 8

x              -

21/a   x    b      =  9

=              =

21            5

Step 2:

Creating the equations:

8 - a - b = 5 => a + b   = 3

(21/a) x b = 9  => 7b  = 3a

Step 3:

Solving both the equations

3a + 3b = 9

7b  + 3b = 9

=> 10b = 9

=> b = 0.9

Step 4:

Find a  using b = 0.9

a + 0.9 = 3 => a = 2.1

Step 5:

Find 8 - a  and 21/a

8 - 2.1 = 5.9

21/a = 21/2.1 = 10

Step 6:

Filling the boxes:

2.1       +   5.9    = 8

x              -

10     x   0.9      =  9

=              =

21            5