Question

13x-5(x+2)=4(2x-1)+7

Answer 1

13x² + 26x - 5x -10 = 8x -4 +7
13x² +21x -10 = 8x -4 +7
13x² + 21x -8x -10 +4 -7 = 0
13x² +13x -13 = 0
x = -b ± √b²- 4 x a x c : 2 a
x= -13 ± √13² - 4 x 13 x -13 : 2 x 13
x = -13 ± 338 : 26
x1= -13 + 338 : 26 = 12'5
x2= -13 -338 :26 = -12'5