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

4b + x = -7
x = -7 - 4b

then substitute the result (-7 - 4b) into the second equation:

3b - 5(-7 - 4b) = 5
3b + (-5 x -7) + (-5 x -4b) = 5
3b + 35 + 20b = 5
3b + 20b = 5 - 35
23b = -30
b = \( \frac{-30}{23} \)
b = -1\(\frac{7}{23}\)

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 x 5b = (6 x 5) (a x b) = 30ab

An equation is two expressions separated by an equal sign. The key to solving equations is to repeatedly do the same thing to both sides of the equation until the variable is isolated on one side of the equal sign and the answer on the other.

A trapezoid is a quadrilateral with one set of parallel sides.

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° - 60° - 52° = 68°

So, d° = 52° + 68° = 120°

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° - 60° = 120°