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.

(8a)(6ab) + (7a²)(6b)
(8 x 6)(a x a x b) + (7 x 6)(a² x b)
(48)(a¹⁺¹ x b) + (42)(a²b)
48a²b + 42a²b
90a²b

The first step to solve a quadratic expression that's not set to zero is to solve the equation so that it is set to zero:

a² + 3a + 1 = -a - 2
a² + 3a + 1 + 2 = -a
a² + 3a + a + 3 = 0
a² + 4a + 3 = 0

Next, factor the quadratic equation:

a² + 4a + 3 = 0
(a + 1)(a + 3) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (a + 1) or (a + 3) must equal zero:

If (a + 1) = 0, a must equal -1
If (a + 3) = 0, a must equal -3

So the solution is that a = -1 or -3

To combine like terms, add or subtract the coefficients (the numbers that come before the variables) of terms that have the same variable raised to the same exponent.

4a + 2a = 6a

A circle is a figure in which each point around its perimeter is an equal distance from the center. The radius of a circle is the distance between the center and any point along its perimeter. A chord is a line segment that connects any two points along its perimeter. The diameter of a circle is the length of a chord that passes through the center of the circle and equals twice the circle's radius (2r).

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

p = x + y + z
p = 14cm + 15cm + 13cm = 42cm