Question

7.5+13.6=12.4+[] work out the missing number

Answer 1

8.7

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Lets take, Missing number as = x

7.5+13.6 = 12.4+x

21.1 = 12.4+x

21.1 - 12.4 = x

x = 8.7

_______

Re-check:-

=> 7.5+13.6 = 12.4+8.7

=> 21.1 = 21.1

Answer 2

Answer:

8.7

Step-by-step explanation:

I'm gonna use algebra for this if you don't mind.

7.5 + 13.6 = 21.1

21.1 = 12.4 + x

Subtract 12.4 from both sides:

21.1 - 12.4 = 12.4 - 12.4 + x

8.7 = x

Reasoning:

First add 7.5 and 13.6 to get 21.1.

You'll get something that looks like this: 21.1 = 12.4 + _

We want a number that adds to 12.4 to make 21.1, so we subtract 21.1 from 12.4 and we get 8.7