Which of the this is a mathematical translation of "A number increased by 7". A. a + 7
B. 7 + a
C. 7a
D. 7/a​

A
the keyword is “increased”. That shows that you need to add instead of multiply. “a” is the secret number. Think of it like a sandwich... the bread is a (the secret number) and the meat is + (increased by) and the other bread is the 7. Hope this helps!:)

The correct answer is A: whenever you see “by #” that number is going to be put at the end of the equation or at least after the variable. “A number increased by 7” in other words, “this number will go up by 7” in equation form equals, (a+7)

Answer is b ,-4x^2 - 13y^2