Answer:
15
Step-by-step explanation:
Let's call the mystery number x.

Hope this helps!
Answer:
50?
Step-by-step explanation:
Because its 50 miles per gallon, so gallon time 50 will be the miles? I'm not sure but i think it is
Start with

Expand both parentheses by multiplying both terms by the number outside:

Sum like terms:

Simplify the "+3" on both sides:

Subtract 2x from both sides:

Divide both sides by 2:
