Explanation:
1. Make 2 parenthesis, extract x and put it in both parenthesis. The first parenthesis will have the sign of the number in the middle +5x, the second parenthesis will have the product of the multiplication of the sign of the second and third number; (+)(-) = -. Then, find 2 numbers that multiplied by each other give the third number as a result and added up or substracted give the result of the number in the middle. Here, 7 times 2 is 14 and +7 -2 = +5
Equal both results to zero.
