I thought of a number, added 7 , multiplied by 3 , subtracted 3,divided by 2 , then multiplied by 12,the rest was 72,what was the number i thought of
As a simple method we could just reverse the order and do the inverse each time:
" I thought of a number, added 7 , multiplied by 3 , subtracted 3,divided by 2 , then multiplied by 12,the rest was 72 "
72 ÷12 = 6
6*2 = 12
12+3 = 15
15 ÷ 3 = 5
5-7 = -2
your number was -2
or
(((x+7)*3) - 3)/2*12 = 72
divide by 12
(((x+7)*3) - 3)/2 = 6
multiply by 2
(x+7)*3) - 3 = 12
(x+7)*3 = 15
x+7 = 5
x = -2
in effect I performed the same steps
To find the number you thought of, let's go step by step through the calculations given:
1. Start with the unknown number (let's call it x).
2. Add 7: x + 7
3. Multiply by 3: 3(x + 7) = 3x + 21
4. Subtract 3: 3x + 21 - 3 = 3x + 18
5. Divide by 2: (3x + 18)/2 = (3/2)x + 9
6. Multiply by 12: 12((3/2)x + 9) = 18x + 108
According to the information provided, the result of these calculations is 72. So, we can set up the equation:
18x + 108 = 72
Now, let's solve for x:
1. Subtract 108 from both sides of the equation:
18x = 72 - 108
18x = -36
2. Divide both sides by 18 to isolate x:
x = -36/18
x = -2
Therefore, the number you initially thought of is -2.
Let's solve this step-by-step.
1. Start with the number you thought of: x
2. Add 7: x + 7
3. Multiply by 3: 3(x + 7)
4. Subtract 3: 3(x + 7) - 3
5. Divide by 2: (3(x + 7) - 3) / 2
6. Multiply by 12: 12((3(x + 7) - 3) / 2)
The result of these calculations should be 72, so:
12((3(x + 7) - 3) / 2) = 72
To solve for x, we can rearrange the equation:
3(x + 7) - 3 = (2 * 72) / 12
3(x + 7) - 3 = 12
Now, simplify the equation:
3x + 21 - 3 = 12
3x + 18 = 12
3x = 12 - 18
3x = -6
x = -6 / 3
x = -2
So, the number you thought of was -2.