when 7 is added to an unknown number the answer is twice the unknown number .what is the unknown number

The unknown number is 7.

Explanation:

If you're adding 7 to it, and it becomes twice of itself. Meaning the unknown number, x. Was multiplied by a factor of 2. So 2x. Or 7+x=2x.

7

Step-by-step explanation:

Let's call the unknown number n.

7 + n

7 + n = 2n

Isolate the variable by subtracting n from each side.

7 = n.

The unknown number is 7.

y=mx+b

step-by-step explanation:

m slope, b y-intercept

b. 1.25 hr

step-by-step explanation:

if you have a constant speed of 60 mph, then you have a ratio between 60 mi. to 1 hr. dividing both sides by 60 we get the ratio

1 mi. to

then mult. both sides by 75 we get the ratio

75 mi. to

simplifying we get

75 mi. to

or 1.25 hr.