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

6c + z = 3
z = 3 - 6c

then substitute the result (3 - 6c) into the second equation:

7c - 4(3 - 6c) = -1
7c + (-4 x 3) + (-4 x -6c) = -1
7c - 12 + 24c = -1
7c + 24c = -1 + 12
31c = 11
c = \( \frac{11}{31} \)
c = \(\frac{11}{31}\)

A monomial contains one term, a binomial contains two terms, and a polynomial contains more than two terms.

The circumference of a circle is the distance around its perimeter and equals π (approx. 3.14159) x diameter: c = π d. The area of a circle is π x (radius)² : a = π r².

A quadrilateral is a shape with four sides. The perimeter of a quadrilateral is the sum of the lengths of its four sides.

Parallel lines are lines that share the same slope (steepness) and therefore never intersect. A transversal occurs when a set of parallel lines are crossed by another line. All of the angles formed by a transversal are called interior angles and angles in the same position on different parallel lines equal each other (a° = w°, b° = x°, c° = z°, d° = y°) and are called corresponding angles. Alternate interior angles are equal (a° = z°, b° = y°, c° = w°, d° = x°) and all acute angles (a° = c° = w° = z°) and all obtuse angles (b° = d° = x° = y°) equal each other. Same-side interior angles are supplementary and add up to 180° (e.g. a° + d° = 180°, d° + c° = 180°).