Answer: Joe has initial amount of $12 ( when he played no game).
Step-by-step explanation:
Given: Joe took $12 to the arcade. Each game cost $.50 to play.
This situation can be modeled with the equation 
Here,
Money Joe has remaining is repreesnted by 'y', and the number of games he plays is represented by 'x'.
Since y-intercept gives the initial value of the function when x=0.
To find y-intercept , we out x=0 in funtion , we get

So , y-intercept of this function is at y=12.
Meaning of the y-intercept in the terms of this problem :
Joe has initial amount of $12 ( when he played no game).
Answer:
1.75*10 to the power of 5
Step-by-step explanation:
start by moving the decimal over until only one number is in front of the decimal. this is because in scientific notation a number can't be higher than 9.
check how many places you move the decimal over (5). 1.75000 needs to be simplified (since that's the point of scientific notation) and can be simplified to 1.75.
the answer is 1.75 multiplied by ten to the power of digits the decimal moved (5) so the answer is 1.75*10 to the power of 5
53-49=4
4 times 12=48. the unknown number is 48