Answer:
Eric's earning is $7
Step-by-step explanation:
Given
Represent Robert's earnings with R and Eric's with E.
[tex]R = 10\\R = 2E - 4[/tex]
Required
What is the value of E?
Substitute 10 for R in the second equation.
[tex]10 = 2E - 4[/tex]
Solve for 2E
[tex]2E = 10 + 4[/tex]
[tex]2E = 14[/tex]
Solve for E
[tex]E = 14/2[/tex]
[tex]E = 7[/tex]
Eric's earning is $7
