Y=x^2+8x+12 find the y-intercept for the parbola

Which equation can be used to solve for the unknown number? seven less than a number is thirteen. n-7=13 7-n=13 n+7=13 n+13=7

The perimeter of a triangle is 69 cm. the first is 5 cm shorter than the second side. the third side is twice as long the first side. find the length of each side

I’m on question 7 it says a covered water tank is in the shape of a cylinder the tank has a 28 inch diameter and a height of 66 inches to the nearest square inch what is the surface area of the water tank