4x - 2y = -20
7x + 2y = -2

(-2, 6)

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDASEquality Properties

Algebra I

Solving systems of equations using substitution/eliminationSolving systems of equations by graphing

Step-by-step explanation:

Step 1: Define systems

4x - 2y = -20

7x + 2y = -2

Step 2: Rewrite systems

4x - 2y = -20

Add 2y to both sides:                    4x = 2y - 20Divide 4 on both sides:                 x = 1/2y - 5

Step 3: Redefine systems

x = 1/2y - 5

7x + 2y = -2

Step 4: Solve for y

Substitution

Substitute in x:                         7(1/2y - 5) + 2y = =-2Distribute 7:                              7/2y - 35 + 2y = -2Combine like terms:                11/2y - 35 = -2Add 35 to both sides:              11/2y = 33Isolate y:                                   y = 6

Step 5: Solve for x

Define original equation:                    7x + 2y = -2Substitute in y:                                     7x + 2(6) = -2Multiply:                                                7x + 12 = -2Subtract 12 on both sides:                   7x = -14Divide 7 on both sides:                        x = -2

Step 6: Graph systems

Check the system.