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).

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

-2c + y = -2
y = -2 + 2c

then substitute the result (-2 - -2c) into the second equation:

c + 7(-2 + 2c) = -5
c + (7 x -2) + (7 x 2c) = -5
c - 14 + 14c = -5
c + 14c = -5 + 14
15c = 9
c = \( \frac{9}{15} \)
c = \(\frac{3}{5}\)

The volume of a cylinder is πr²h:

v = πr²h
v = π(5² x 6)
v = 150π

When solving an equation with two variables, replace the variables with the values given and then solve the now variable-free equation. (Remember order of operations, PEMDAS, Parentheses, Exponents, Multiplication/Division, Addition/Subtraction.)

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)(2ab) + (5a²)(3b)
(6 x 2)(a x a x b) + (5 x 3)(a² x b)
(12)(a¹⁺¹ x b) + (15)(a²b)
12a²b + 15a²b
27a²b