well first you have to do distributive property with the parenthesis, multiply 5 times x and 5 times 3 to get 5x and 15 now you have 14+5x+15-7x, now add common like terms(these are terms taht have the same number variable or both) so your common numbers will be 14 and 15, and 5x and -7x now add or subtract them to get -2x+29 now you have to set x by itself so set this binomial equal to 0 to get -2x+29=0 subtract the 29 from both sides and get -2x=-29 now divide 2 by both sides to get x=29/2
Hope this helps