Part a: the first cereal is y=7x and the second one is y=10x so they are $3 apart.
part b: y=7*4 (28) and y=10*4 (40) is $12 apart so she will save $12 each month.
I don't know about how to put that in standard form, but an equation has to have an equals sign... So, that would be an equation.
Answer:
x = 12
Step-by-step explanation:
10x = 120 original equation
10x/10 = 120/10 divide both sides by 10
x = 12 simplify
Check work:
10(12) = 120
120 = 120 (true)
