( 6 - x)² = 121
( 6 - x)( 6 - x) = 121
36 - 12x + x² - 121 = 0
x² - 12x - 85 = 0
D = b² - 4ac = ( - 12)² - 4 × 1 × ( - 85) = 144 + 340 = 484 = 22²
x₁ = (12 + 22) / 2 = 17
x₂ = (12 - 22) / 2 = - 5
( 5x + 1)² = 400
( 5x + 1)( 5x + 1) = 400
25x² + 10x + 1 - 400 =0
25x² + 10x - 399 = 0
D = b² - 4ac = 10² - 4 × 25 × ( - 399) = 100 + 3990 = 4090
x₁,₂ = - 10₊/₋√4090/ 50
3,6^2-3,6*1,2+2,4^2 = =3,6(3,6 - 1,2)+2,4^2==3,6*2,4 + 2,4^2 = 2,4(3,6 + 2,4) = 2,4*6 = 14,4
{y=2x-4
{5x-4(2x-4)=13
5x-8x+16=13
-3x=-3
x=1
y=2x-4=2×1-4=2-4=-2
{x=1
{y=-2