What does twice the product of 3 and a number exceeds the sum of the number and 80 by 10. what is that number?

So 2(3x)=x+80+10
distribute
6x=x+90
subtract x from both sides
5x=90
divide both sides by 5
x=18

Let x be the number
twice the product of 3 and a number means 
2(3x)

the sum of the number and 80 by 10 means
 x+80+10
putting this altogether creates an equation

2(3x)=x+80+10
6x=x+90 (expanded the brackets on the left hand side and added 80 +10 on the left)
5x=90 (subtracted x to both sides)
x=90/5
x=18

Therefore the number is 18. 

Answer:

$4034.40

step-by-step explanation:

the perimeter of the field is the sum of the lengths of the four sides:

47 yd + 158 yd + 47 yd + 158 yd = 410 yd

the cost of 3 ft (1 yd) of fence is 3×$3.28 = $9.84.

so the cost of jake's wood perimeter fance is

(410 yd) × ($9.84 /yd) = $4034.40