Answer:
<h3>
Therefore total amount of money that he got is = $(5+0.50x) [ x = number of correct math]</h3>
Step-by-step explanation:
Given, Gilberto's grandfather gives him $5 for his birthday and then$0.50 for each math he answers correctly on his math exam for the year.
Let , the number of math that he answers correctly on his his math exam for the year is x
Therefore he got = $(0.50× x) =$ 0.50x for doing correct math.
Therefore total amount of money that he got is = $(5+0.50x) [ x = number of correct math]

this is the answer, its pretty simple. I'm not sure the mathematical procedures but if you plug in 7 you get 49. Then all you got to do is subtract by 7, because the question states the number is the same. So basically,
A) 6u+3u+4-15= (9u-11) <---answer ;) B)-1-2u-9-(-5u)=(3u-10)<--answer C) 7u+25+(-10u)-16= (-3u+9)<--answeeer