Answer:Hello
I think it's 12
Step-by-step explanation:
Actually at first you should plus this tow parameters:2x-3x+10
and then you can put(-2)instead (x).
Now you find answer.
..........................................
-3 = x + x + x
-3 = 3x
-3/3 = x
x = -1
When Sam is 13 his mother will be 39 which is 3 times as old as he is. So Sam's mother will be 3 times as old as Sam will be in 11 years. (Your answer is 11 years.)
Ok so im not good with words and math, but i am going to try my best to explain it. first you will take 45/60 which is the 45 miles per hour. next you will put it equal to 40/x. x is how many minutes. they are set equal to each other because they are the same ratio. (i honestly dont know why you cross multiply, but you just do). you then multiply 40*60 and 45*x. this gives you 2400=45x. you then divide both sides by 45 and get 53 1/3 minutes. or 53 minutes and 20 seconds