Answer:
x=2
Step-by-step explanation:
Original width = 6
New width 6+x+x
Orignal length 12
New length 12+x+x
A = l*w
160 = ( 6+2x) ( 12+2x)
Factor
160 = 2( 3+x) 2(6+x)
Divide each side by 4
40 = (3+x) (6+x)
FOIL
40 = 18+ 6x+3x+ x^2
40 = 18 +9x+x^2
Subtract 40 from each side
0 = x^2 +9x -22
Factor
0 = (x +11) (x-2)
Using the zero product property
x +11 =0 x-2 =0
x= -11 x=2
Since we cannot have a negative sidewalk
x =2
The upper comment is correct
Answer:
e. 10√30
Step-by-step explanation:
In this right triangle geometry, all of the right triangles are similar. This means that the ratio of long side to hypotenuse is the same for all triangles:
x/(10+50) = 50/x
Multiplying by 60x, we have ...
x^2 = 3000
x = 10√30 . . . . . take the square root. Matches choice E.
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<em>Comment on estimating</em>
You're looking for x. Examining the figure, you see that x is the long side of the triangle with hypotenuse 10+50=60, so it will be shorter than that value. x is also the hypotenuse of the triangle with long side 50. So, x will be longer than 50.
The only answer choice with a value between 50 and 60 is choice E.
You don't even need to know how to find x. You only need to know that the hypotenuse is the longest side in a right triangle.
Actually, there would be no solution because the w's cancel out so that leaves -6=-9 and that is not true.
Answer:
£8.10
Step-by-step explanation:
Divide £10.80 by 4 to find the cost of 1 Kg, then multiply this by 3
£10.80 ÷ 4 = £2.70 ← cost of 1 Kg , then
cost of 3 Kg = 3 × £2.70 = £8.10
