If y=3x+5 ,what is the value of y when x=12

Evaluate the expression for the given value of the variable 2×(c2-5) for c=4

Me, the vertices of quadrilateral coat are c(2,0), o(7,0), a(7,2) and t(2,2). prove that coat is a rectangle.

Solve this riddle: i am an odd number. i an less than 100. the some of my digit is 12. i am a multiple of 15. what number am i?