*1) **Identify the coefficients of each equation and say whether it is complete or not:*

*a) 5x ^{2} - 3x - 2 = 0*

*b) 3x ^{2} + 55 = 0*

*c) x ^{2} - 6x = 0*

*d) x ^{2} - 10x + 25 = 0*

*2) Find the roots of the equations: *

*a) x ^{2} - x - 20 = 0*

*b) x ^{2} - 3x -4 = 0 *

*c) x ^{2} - 8x + 7 = 0*

*3) Of the numbers -2, 0, 1, 4, which of them are roots of equation x ^{2}-2x-8 = 0?*

*4) The number -3 is the root of equation x^{2} - 7x - 2c = 0. Under these conditions, determine the value of the coefficient c:*

*5) If you multiply a real number x by yourself and the result subtract 14 you will get five times the number x. What is this number?*