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

7b + y = -3
y = -3 - 7b

then substitute the result (-3 - 7b) into the second equation:

2b - 4(-3 - 7b) = 4
2b + (-4 x -3) + (-4 x -7b) = 4
2b + 12 + 28b = 4
2b + 28b = 4 - 12
30b = -8
b = \( \frac{-8}{30} \)
b = -\(\frac{4}{15}\)

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°).

To multiply binomials, use the FOIL method. FOIL stands for First, Outside, Inside, Last and refers to the position of each term in the parentheses:

(y - 6)(y + 3)
(y x y) + (y x 3) + (-6 x y) + (-6 x 3)
y² + 3y - 6y - 18
y² - 3y - 18

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:

z² - 2z - 75 = -z - 3
z² - 2z - 75 + 3 = -z
z² - 2z + z - 72 = 0
z² - z - 72 = 0

Next, factor the quadratic equation:

z² - z - 72 = 0
(z + 8)(z - 9) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (z + 8) or (z - 9) must equal zero:

If (z + 8) = 0, z must equal -8
If (z - 9) = 0, z must equal 9

So the solution is that z = -8 or 9

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.

2a⁸ + 6a⁸ = 8a⁸