To do this problem we need to get a common denominator in the numerator which is going to be three a * a + 4. So the first term is got to get multiplied top and bottom by 3A and the next terms got to be multiplied top and bottom by a + 4. Once we get the denominators the same, we just add the numerators. So a * 3 a is three a ^2 + 5 times a 5A plus 5 * 420 three a ^2 + 5 A+ 20 can't factor, so we're going to leave that alone. Looking at the denominator, we get a over the quantity 7 * a + 4 + 3 / a. So the common denominator for the bottom is going to be 7 A a + 4. The first term we have to multiply the top and bottom by A. The second term, we're going to multiply the top and bottom by seven a + 4. When we distribute there, we get a ^2 + 21 A+ 84. Because it's division, we're going to flip them and multiply. We're going to flip the one that's in the denominator. So we get three a ^2 + 5 A+ 20 / 3 A times A + 4 * 7 A A + 4 / a ^2 + 21, A+ 84. So the A+ fours on top and bottom will cancel, The single A's on top and bottom will cancel, leaving A 7 ( 3 A squared plus 5A plus 20 / 3 times the quantity a ^2 + 21, A+ 84.