Answer:
7
Step-by-step explanation:
We want to find the number 4-digit of positive integers n such that removing the thousands digit divides the number by 9.
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Let the thousands digit be 'd'. Then we want to find the integer solutions to ...
n -1000d = n/9
n -n/9 = 1000d . . . . . . add 1000d -n/9
8n = 9000d . . . . . . . . multiply by 9
n = 1125d . . . . . . . . . divide by 8
The values of d that will give a suitable 4-digit value of n are 1 through 7.
When d=8, n is 9000. Removing the 9 gives 0, not 1000.
When d=9, n is 10125, not a 4-digit number.
There are 7 4-digit numbers such that removing the thousands digit gives 1/9 of the number.
Answer:
D
Step-by-step explanation:
Your answer would be x = 12
The triangle sum theorem states that the 3 angles in a triangle equal 180.
Since we have a 90 degree angle shown, we can add it to the other two and set it equal to 180.
30+90+6x-12=180
108+6x=180
6x=72
x=12
