Answer:
They can paint 18. 66 sq ft with 3 gallons of paint.
Step-by-step explanation:
Total area painted = 280 sq ft
Total gallons of paint used = 45
So, 45 gallons of paint painted 280 sq ft.
⇒ By UNITARY METHOD,
1 gallon of paint paints 
sq ft
So, area painted by 1 gallon = 6.22 sq ft
⇒ area painted by 3 gallon = 6.22 sq ft x 3 = 18. 66 sq ft
So, they can paint 18. 66 sq ft with 3 gallons of paint.
First combine like terms:
6n-2n = 4n
7n-2=4n
subtract 7n from both sides
7n-2=4n
-7n -7n
-2=-3n
divide -2 on both sides.
n=1.5
You should write numbers in as many ways as you possibly can to make new connections in your brain. Knowing how to write numbers in many different ways can help you solve complex problems more easily. Doing this can also reinforce the mathematical principles and logic you have memorised.
Writing one in many different ways:
1=1/1=2/2=3/3=4/4=(-1)/(-1)=(-2)/(-2)
=1.0=1.00=1.000=(1/2)+(1/2)=(1/3)+(1/3)+(1/3)
=(1/4)+(1/4)+(1/4)+(1/4)
Writing a half in many different ways:
1/2=(1/4)+(1/4)=(1/6)+(1/6)+(1/6)
=(1/8)+(1/8)+(1/8)+(1/8)=4*(1/8)
=2/4=3/6=4/8=5/10=0.5=0.50
etc...etc...
m+f=38
(f-4)^2=m-4
f^2=m IF their age is 30 combined
4^2=16
16=16
Fred is 4, Mabel is 16.
