(Middle school math) please help, thank you!
2 answers:
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<h2>The required positive number is 7.</h2>
Step-by-step explanation:
Let the number = x
To find, the positive number = ?
According to question,
⇒ - 3x - 28 = 0
By Factorisation method,
⇒ - 7x + 4x - 28 = 0
⇒ x(x - 7) + 4(x - 7) = 0
⇒ (x - 7)(x + 4) = 0
⇒ x - 7 = 0 or, x + 4 = 0
⇒ x = 7 or, x = - 4 [ - 4 is a negative number)
⇒ x = 7
Thus, the required positive number is 7.
The expressions for the width, W, and area, A, of the rectangle in terms of L are:
- W =
- L
- A =
The expression for the perimeter of a rectangle is given as:
P = 2(L + W)
where L is its length and W its width
a. Given that the perimeter of the rectangle is 13 feet, then;
13 = 2(L + W)
divide through by 2
= L + W
So that;
W = - L
The required formula for the width as a function of L is: W = - L
b. Area of a rectangle can be expressed as;
A = L * W
substitute the expression for width in that of area to have
A = L * ( - L)
= L -
A =
The expression for the area A is: A =