Not sure how to work this problem out. i keep getting the incorrect answer

First you multiply because of order of operations

12/35 + 10/30

Then you find the common denominator to add which would be 210

72/210 + 70/210 = 142/210

You can simply this to 71/105

Follow the order of operations parentheses, exponents, multiplication and division left to right, and addition and subtraction left to right. So no parentheses or exponents so skip those. so multiply the first to fraction. No LCD required. Now you have 12/35+5/6 * 2/5 and 5/6 * 2/5= 10/30 so there is 12/35+10/30 NOW you need LCD. which is 210 so multiply the top and bottom of 12/35 by 6 since 35*6=210 and you have 72/210. Multiply the numerator of 10/30 by 7 since 7*30=210, which gives you 70/210 so your equation now is 72/210 + 70/210 and since the denominator stays the same you have 142/210 and simplified that gives you 71/105