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.
There are 3 ways of solving a simultaneous problem, substitution method, elimination method and Gauss-Jordan method. I'm gonna use the substitution method since it's easier and i think it would suit your level more.
First let's try solving for y since it's easier to start with.
Firstly we have to find an equation for x:
Great, now we can use the substitution method to find the value of y using the first equation:
Now we know that y=1 we can solve the first equation we made:
And the answer is
Double check:
And that's our final answer! (4,1)