Solve the following system of equation using the method of substitution. Show the work that leads to your answer.
y=-2x-10
2x + 5y = 6

Step-by-step explanation:

y = -2x - 10       (I)

2x + 5y = 6      (II)

Substitute y = -2x - 10 in equation (II)

2x + 5 (-2x -10) = 6

2x  + (-2x) *5 + (-10) *5 = 6

2x - 10x - 50 = 6

-8x - 50 = 6

        -8x = 6 + 50

       -8x = 56

          x = 56/-8

x = -7

Plugin x = -7 in equation (I)

y = -2*(-7) - 10

  = 14 - 10

y = 4

x= -3 and

step-by-step explanation:

to find the roots of a cubic, use division or factoring to find the factors then set equal to 0. as this is a difference of cubes, it factors into

where a is the cube root of .

here   this is 27 and the cube root of 27 is 3. so we write using the form:

.

set each factor to 0 and solve for x.

x-3=0

x=3

the quadratic expression does not factor and must be solved using the quadratic formula.

where a = 1, b=3, and c=9

this cubic has two complex roots.

i found two solutions,   n = 2 • ± √3 = ± 3.4641

step-by-step explanation: