Ok so your equation is 9x+61 and since you said that the X=7 you would replace the X with a 7 in the equation so now you have 9(7)61 and if the two numbers where together that means you would multiply 9x7 which is 63 and once you have that then you would just simply add 63+61 and you would get your total amount of 124.
I hope I explain this well and clear for other equations that may be similar to this.
