(3x-7)²- (5x+1)(2x-5) = -3 - x²
9x² - 42x + 49 - 10x² + 23x + 5 = -3 - x²
-x² - 19x + 54 = -3 - x²
-x² + x² - 19x = -54 -3
-19x = -57
x = 57 : 19
x = 3
(3x-7)²- (5x+1)(2x-5) = -3 - x²
9x² - 42x + 49 - 10x² + 23x + 5 = -3 - x²
-x² - 19x + 54 = -3 - x²
-x² + x² - 19x = -54 -3
-19x = -57
x = 57 : 19
x = 3
9x²-42x+49-(10x²-23x-5)=-3-x²
9x²-42x+49-10x²+23x+5=-3-x²
-x²-19x+54=-3-x²
-19x+54=-3
-19x=-3-54
-19x=-57
x=3