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

-8a + y = -1
y = -1 + 8a

then substitute the result (-1 - -8a) into the second equation:

4a + 8(-1 + 8a) = -9
4a + (8 x -1) + (8 x 8a) = -9
4a - 8 + 64a = -9
4a + 64a = -9 + 8
68a = -1
a = \( \frac{-1}{68} \)
a = -\(\frac{1}{68}\)

The area of a trapezoid is one-half the sum of the lengths of the parallel sides multiplied by the height:

a = ½(b + d)(h)
a = ½(4 + 2)(2)
a = ½(6)(2)
a = ½(12) = \( \frac{12}{2} \)
a = 6

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.

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 + 6a = 8a

An isosceles triangle has two sides of equal length. An equilateral triangle has three sides of equal length. In a right triangle, two sides meet at a right angle.