What is the decimal multiplier to increase by 21%?

What is the perimeter, p, of a rectangle that has a length of x + 8 and a width of y − 1? p = 2x + 2y + 18 p = 2x + 2y + 14 p = x + y − 9 p = x + y + 7

The floor plan of a room has a scale of 2.5 in.: 35 ft. in the drawing, the length of the room is 8 in. and the width of the room is 6 in. what is the perimeter of the actual room?

Three times the sum of a number and seven is negative thirty-six. what is the number?