Question

I think of a number. If I subtract 9 from it and multiply this difference by 4, the

result is 128.

Answer 1

you were thinking of 41

Explanation:

(x-9)*4=128

(x-9)=128/4

(x-9)=32

x=32+9

x=41

Answer 2

41

Explanation:

Let n be the number

Subtract 9

n-9

Multiply this by 4

4(n-9)

The result is 128

4(n-9)=128

To find the number divide each side by 4

4(n-9)/4=128/4

n-9 = 32

Add 9 to each side

n-9+9 = 32+9

n = 41