Answer
$8x+11$
Work Step by Step
RECALL:
The distributive property states that for any real numbers a, b, and c:
$ac+bc= (a+b)c$
Add the polynomials by regrouping the terms and then combining like terms using the distributive property to obtain:
$(3x+4)+(5x+7)
\\= (3x+5x)+(4+7)
\\=(3+5)x + 11
\\=8x + 11$