Answer:
7.07
Step-by-step explanation:
<h2><u>Length</u></h2>
a square has equal length on each side
hence is the perimeter is 20 it means that :
each side is 20/4 = 5
we can make a diagonal line which create 3 right angled triangles
2 sides of the triangle are 5 , this is the base and the height
to find the length we can make use of the Pythagoras theorem
c^2 = a^2 + b^2
c is the hypotenuse ( the diagonal;)
a and b are the opposite and adjacent
hence :
c^2 = 5 ^2 + 5^2
c^2 = 50
c = 
c = 7.071
to 3sf
<h3><u>diagonal length = 7.07</u></h3>
Answer
Find out the how much does one apple cost .
To prove
Let us assume that the number of bananas be x .
Let us assume that the number of apples be y .
As given
At a greengrocer, two bananas and one apple cost $1.16 .
Than the equation becomes
2x + y = 1.16
one banana and one apple cost $0.71.
Than the equation becomes
x + y = 0.71
Subtracting x + y = 0.71 from 2x + y = 1.16
2x - x + y - y = 1.16 - 0.71
x = 0.45
Put in the equation x + y = 0.71
0.45 + y = 0.71
y = 0.71 - 0.45
y = $0.26
Therefore the cost of the one apple is $0.26 .