Answer:
2x+15=33
Step-by-step explanation:
Let n be the number of days he has been doing sit ups, not counting the first day. Since he does 2 more sit-ups for each day, then the number of additional sit-ups is 2n.
Since he started doing 15 sit-ups on the first day, the total number of sit-ups
after x days would be 2n+15.
Since he did a total of 33 sit ups today, then 2n+15=33
Answer:
The answer is 
Step-by-step explanation:
when writing scientific notation, there must be one number to the left of the decimal point.
To achieve this in this problem, you need to move the decimal point 3 times to the right.
because you are moving the point to the right, the exponent will be negative.
*rule of thumb: moving the decimal to the left will give you a positive exponent, moving to the right will give you a negative exponent*
therefore you answer should be written as:

hope this helps :)
Answer:
4/5
Step-by-step explanation:
The surface area of a sphere is 4r^2pi, so dividing 100 by 4pi gives a result of 25/pi. Taking the square root and rationalizing the denominator, we have 5sqrt(pi)/pi as the radius of the sphere.
Answer:
140 units²
Step-by-step explanation:
1/2bh=
1/2(15-5)(30-2)=
1/2 (10)(28)=140