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 + 4a - 11 = -4a - 2
a² + 4a - 11 + 2 = -4a
a² + 4a + 4a - 9 = 0
a² + 8a - 9 = 0

Next, factor the quadratic equation:

a² + 8a - 9 = 0
(a - 1)(a + 9) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (a - 1) or (a + 9) must equal zero:

If (a - 1) = 0, a must equal 1
If (a + 9) = 0, a must equal -9

So the solution is that a = 1 or -9

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

p = x + y + z
p = 5cm + 6cm + 11cm = 22cm

An exterior angle of a triangle is equal to the sum of the two interior angles that are opposite:

d° = b° + c°

To find angle c, remember that the sum of the interior angles of a triangle is 180°:

180° = a° + b° + c°
c° = 180° - a° - b°
c° = 180° - 22° - 25° = 133°

So, d° = 25° + 133° = 158°

A shortcut to get this answer is to remember that angles around a line add up to 180°:

a° + d° = 180°
d° = 180° - a°
d° = 180° - 22° = 158°

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.

2a - 5a = -3a

A cylinder is a solid figure with straight parallel sides and a circular or oval cross section with a radius (r) and a height (h). The volume of a cylinder is π r²h and the surface area is 2(π r²) + 2π rh.