Answer: L = 29cm
Step-by-step explanation:
Let's go!!
To find any rectangle area, you have to apply this formula: A = L . w , where L is the length and w is the width.
So, we have w = L - 13 (the width is 13 less than the Length) and then, perimeter is 90 cm.
Well, I hope you remember that the perimeter of rectangle is 2L + 2W. In this case, 2L + 2w = 90
Then, you might to solve this system of equation:
2L + 2w = 90
w = L - 13
Simplifying the first equation, you'll have L + w = 45 (you can divide everything of 2).
Our new system:
L + w = 45
w = L - 13
Using the substituition method:
L + L - 13 = 45
2L = 58
L = 29 cm
the width is 29 - 13 = 16 cm
The answer is 30. 360/12.
(trying to isolate/get x by itself in the equation)
5(x + 6) = 50 Distributive property [distribute 5 into (x + 6)]
5x + 30 = 50 Subtraction [subtract 30 on both sides of the equation]
5x = 20 Division [divide 5 on both sides]
x = 4
Subtraction then division, the 2nd option
Answer:
r = - 7, r = - 5
Step-by-step explanation:
Given
r² = - 12r - 35 ( add 12r to both sides )
r² + 12r = - 35
To complete the square
add ( half the coefficient of the r- term )² to both sides
r² + 2(6)r + 36 = - 35 + 36
(r + 6)² = 1 ← take the square root of both sides )
r + 6 = ± 1 ( subtract 6 from both sides )
r = - 6 ± 1, thus
r = - 6 - 1 = - 7 or r = - 6 + 1 = - 5
