The perimeter of a rectangle is the sum of all its sides. As a formula, this is
P = w + w + l + l = 2w + 2l = 2(w + l),
where P is perimeter, w is the width, and l is length.
Let's apply this formula to your question and substitute given information, then solve for l.
P = 2(w + l)
10x + 6 = 2(3x - 3 + l).
10x + 6 = 6x - 6 + 2l
4x +12 = 2l
l = 2x + 6
Answer:

Step-by-step explanation:
11.7
Answer: You shouldn't hate trig.
Step-by-step explanation:
SinΘ= opposite/hypotenuse
SinΘ=y/x
Sin(16) = 9/x
x = 9/Sin(16)
x= 32.7 cm
This is a simple equation:
x - 7 < 14
x < 14 + 7
x < 21
→ Many people think that because there is not "=" sign they don't flip the sign of what in this case is -7. But actually, the symbols "<" and ">" act as the equal sign. This rule doesn't apply to positive number, only negative.
Hope it helped,
BioTeacher101
(If you have any questions, feel free to ask them in the comments)
Let the legs of the triangle be a and b, and the hypotenuse c.
Your first instinct might tell you to use the Pythagorean theorem to go about solving this because

. This works, but it is slow.
The fastest way to solve this is to recognize that the right triangle is a special triangle where the ratio of the sides are 3:4:5. This means that if the legs are 9 and 12, then the hypotenuse is 15 because 3*3 is 9, 3*4 is 12, and 3*5 is 15.