Perimeter is equal to the sum of the four sides:

p = a + b + c + d
p = 5 + 5 + 8 + 5
p = 23

To multiply monomials, multiply the coefficients (the numbers that come before the variables) of each term, add the exponents of like variables, and multiply the different variables together.

(6a)(5ab) + (3a²)(8b)
(6 x 5)(a x a x b) + (3 x 8)(a² x b)
(30)(a¹⁺¹ x b) + (24)(a²b)
30a²b + 24a²b
54a²b

You need to find the value of b so solve the first equation in terms of y:

5b + y = 5
y = 5 - 5b

then substitute the result (5 - 5b) into the second equation:

-7b - 8(5 - 5b) = -3
-7b + (-8 x 5) + (-8 x -5b) = -3
-7b - 40 + 40b = -3
-7b + 40b = -3 + 40
33b = 37
b = \( \frac{37}{33} \)
b = 1\(\frac{4}{33}\)

The perimeter of a triangle is the sum of the lengths of its sides:

p = x + y + z
p = 5cm + 13cm + 5cm = 23cm

To solve this equation, repeatedly do the same thing to both sides of the equation until the variable is isolated on one side of the > sign and the answer on the other.

9b - 1 > 9 - 3b
9b > 9 - 3b + 1
9b + 3b > 9 + 1
12b > 10
b > \( \frac{10}{12} \)
b > \(\frac{5}{6}\)