7ab+5 is the simplest it can be
Add 12 to both sides resulting in 5a = 60 and then divide both sides by 5 which results in a = 12 so your answer will be a = 12
I'm assuming that when you wrote "(7x/2-5x+3)+(2x/2+4x-6)," you actually meant "<span>(7x^2-5x+3)+(2x^2+4x-6). Correct me if I'm wrong here.
</span><span>+(7x^2-5x+3)
</span><span>+(2x/2+4x-6)
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=9x^2 - x - 3 (answer) </span>
Rectangle Area = length • width
5x • (x + 2) = area
(5x^2 + 10x) is the area, with no further ways to simplify.