Area of a rectangle of length L and width W is A = LW.
Here, A = 60 ft^2 = (12 ft)(2x-3 ft). Let's find the values of x for which the area =60 ft^2, and then the values of x for which the area is greater than 60 ft^2.
60 = 12(2x-3) becomes 5 = 2x - 3 after dividing both sides by 12.
Adding 3 to both sides of this last equation results in 8 = 2x, so x = 4.
Does (12 ft)(2[4 ft] - 3) = 60? Does (12 ft)(5 ft) = 60 sq ft? YES.
The area of this rectangle will be greater than 60 sq ft if x>4 ft. (answer)

From Left side:


NOTE: sin²θ + cos²θ = 1






Left side = Right side <em>so proof is complete</em>
Well first you would start by setting up with a proportion.
In total, the girls paid $54+$22= $76
Thus 1 sister contributed $54/$76=x/100
The other sister contributed $22/$76=x/76
For each proportion, cross-multiply and simplify to get the percentage. The percentage will be the x